Food Technology
Maryam Akbari govarchin galeh; Mohammad Javad Varidi; Mehdi Varidi; Hanieh Yarabbi
Abstract
Introduction Mayonnaise is one of the world’s most popular sauces. It is a semi-solid oil-in-water emulsion made by mixing vegetable oil, egg yolk, water, vinegar, and other ingredients. Due to the high calorie and cholesterol content of egg yolks, excessive consumption of mayonnaise can lead ...
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Introduction Mayonnaise is one of the world’s most popular sauces. It is a semi-solid oil-in-water emulsion made by mixing vegetable oil, egg yolk, water, vinegar, and other ingredients. Due to the high calorie and cholesterol content of egg yolks, excessive consumption of mayonnaise can lead to health-related problems. Major issues faced by mayonnaise producers include fat oxidation during storage, which leads to off-flavor and taste, as well as reduction in nutritional value and food safety. These factors may negatively affect on the consumer acceptance of mayonnaise. With increasing consumer demand for low-fat and low-cholesterol foods, low-fat mayonnaise has significant consumption potential. One of the consumer demands is to reduce the fat content in mayonnaise and salad dressing. Fats play many functional roles in food emulsions, contributing to the taste, appearance, texture, and shelf life of the product in specific ways. Therefore, it is challenging to maintain the quality of traditional products when preparing low-fat foods. It is possible to select specific fat substitutes in particular amounts to create a product with a texture similar to traditional mayonnaise. Light mayonnaise often contains certain fats added to help stabilize the emulsion and thicken its consistency. This research studied the possibility of using aloe vera gel as partial fat substitute in mayonnaise.Materials and MethodsAll the powdered ingredients were mixed together with eggs, water, and half of the required amount of vinegar in a blender for 3 minutes. To form an emulsion, oil was added in two stages while stirring together with starch and gums for 5 minutes. Mixing oil and the aqueous phase simultaneously leads to the formation of a water-in-oil emulsion. Finally, the remaining vinegar was added and mixed for 3 minutes until the fat particles were evenly dispersed in the sauce. Aloe Vera gel was also added in proportion to the reduction of oil according to the formulation of the samples. The optimal mixture design was used for three independent variables: oil A 15-60%, gel B 0-55%, and water C 0-10%. The multiple combinations of these variables led to an experimental design with 16 samples that were determined using Design Expert software, and the physicochemical, rheological, and textural characteristics of the samples were investigated. Additionally, suitable regression equations and mixed contour diagrams were obtained by this software for each response.Results and DiscussionThe results showed that increasing the replacement percentage of aloe vera gel and decreasing the percentage of oil led to an increase in pH and a decrease in acidity, stability, textural properties, and transparency of the samples. To describe the rheological properties, Bingham's model was used, and the viscosity parameters and Bingham's yield stress were investigated with an increasing the percentage of aloe vera gel replacement. Additionally, the apparent viscosity of the samples exhibited a decreasing trend and thinning behavior with shear. These changes in characteristics are attributed to the effect of adding fat to the mayonnaise formulation. The optimal values of independent variables in the production of low-fat mayonnaise were oil (40%), aloe vera gel (30%) and water (0%), respectively.ConclusionThis research showed that aloe vera gel can be used in the formulation of mayonnaise as apartial substitute to oil. Due to the strong demand from consumers for this product, reformulating this high-fat emulsion is a fundamental need in the food industry. The use of aloe vera gel offers many benefits, including reducing cholesterol and fat levels overall, increasing microbiological stability, and, in some cases, lowering manufacturing costs.AcknowledgementThanks to the staff and research and educational officials of Ferdowsi University of Mashhad (Project Code: 2663532).
Food Technology
Massoumeh Mehraban Sangatash; Maryam Dadras-Moghadam; Seyed Ali Mortazavi; Hanieh Yarabbi
Abstract
The increasing growth of cardiovascular diseases, high blood pressure, and hardening of the vessel walls as well as obesity in many countries has made low-fat and low sodium pizza cheese one of the subjects of study all over the world. The effects of four important independent variables including inulin ...
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The increasing growth of cardiovascular diseases, high blood pressure, and hardening of the vessel walls as well as obesity in many countries has made low-fat and low sodium pizza cheese one of the subjects of study all over the world. The effects of four important independent variables including inulin (0-0.025 %), pre-gelatinized starch (0-0.5 %), NaCl (0.35-1%), and KCl (0.35-1%) were studied. The fat content of imitation pizza cheese was significantly decreased to 11.91% with the increased levels of inulin and starch substitution (p<0.05). Also, its moisture and pH values were significantly different (p < 0.05). The increased levels of pre-gelatinized starch and inulin reduced hardness (from 5.04 to 3.55) and adhesiveness (from 4368.89% to 1640.54%), however, increased cohesiveness (from 0.365 to 0.43) and springiness (from 0.456 to 0.545). NaCl and KCl increased the hardness of the product. Inulin and starch led to decrease the a* value. The b* value decreases with the increase of inulin and increases with the increase of modified starch. The formulation containing 0.19% inulin, 0.4% pre-gelatinized starch, 0.35% NaCl, and 0.50% KCl was found as the optimal formulation for low-fat imitation cheese. Results of scanning electron microscope (SEM) images revealed that inulin crystals were accumulated in the continuous phase, which this can lead to important changes in the sensory and textural properties. The study concludes that inulin or starch can be used to replace up to 3.6% of fat in the imitation pizza cheese and 0.35% NaCl-0.50% KCl to lower the sodium content of the product.
Food Chemistry
Negar Soleimanpoor Tamam; Akram Arianfar; Vahid Hakimzadeh; Bahareh Emadzadeh
Abstract
Introduction Gelatin is one of the most widely used colloidal proteins, which has unique hydrocolloidal property. Gelatin is derived from collagen by changing the thermal nature. This product is widely used in food, pharmaceutical, biomedical, cosmetic and photography industries. Global gelatin ...
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Introduction Gelatin is one of the most widely used colloidal proteins, which has unique hydrocolloidal property. Gelatin is derived from collagen by changing the thermal nature. This product is widely used in food, pharmaceutical, biomedical, cosmetic and photography industries. Global gelatin demand for food and non-food products is increasing. Two important properties of nanoparticles are: Increasing the surface-to-volume ratio of nanoparticles causes the atoms on the surface to have a much greater effect on their properties than the atoms within the particle volume. The effects of quantum size, which is the second feature. Methods for preparing nanoparticles from natural macromolecules: In general, two major methods for making protein nanoparticles have been reported Emulsion-solvent evaporation method and sedimentation or phase separation method in aqueous medium. Numerous methods have been reported for the preparation of nanoparticles from natural macromolecules. The first method is based on emulsification and the second method is based on phase separation in aqueous medium. In the first method, due to the instability of the emulsion, it is not possible to prepare nanoparticles smaller than 500 nm with a narrow particle size distribution. Therefore, coagulation method or anti-solvent method which is based on phase separation was proposed to prepare nanoparticles from natural macromolecules. Materials and Methods Type B (cow) gelatin was purchased from processing company with Bloom 260-240 food and pharmaceutical Iran solvent gelatin solution of 25% aqueous acetate glutaraldehyde from Iran Neutron Company. Two-stage anti-solvent method was used to produce gelatin nanoparticles. Then, to form nanoparticles, acetone was added dropwise while stirring until the dissolved acetone begins to change color and eventually turns white, which indicates the formation of nanoparticles. Finally, glutaraldehyde solution was added for cross-linking and finally centrifuged. Results and Discussion The results showed that with increasing gelatin concentration, nanoparticle size and PDI increased significantly. According to the announced results, the solvent has a direct effect on the size. Therefore, the best mixing speed is determined to achieve the smallest particle size. Zeta potential is the best indicator for determining the electrical status of the particle surface and a factor for the stability of the potential of the colloidal system because it indicates the amount of charge accumulation in the immobile layer and the intensity of adsorption of opposite ions on the particle surface. If all the particles in the suspension are negatively or positively charged, the particles tend to repel each other and do not tend to accumulate. The tendency of co-particles to repel each other is directly related to the zeta potential. Fabricated gelatin nanoparticles have a stable structure, and are heat resistant. These nanoparticles are ready to be used to accept a variety of aromatic substances, compounds with high antioxidant properties, a variety of vitamins and heat-sensitive substances. ConclusionThe results of this study showed that the optimal conditions for the production of a particle of 88.6 nm at 40 ° C, the volume of acetone consumption was 15 ml, concentration 200 mg and speed 1000 rpm, and the morphology of gelatin nanoparticles have resistant, spherical polymer structure and mesh with a smooth surface that can be clearly seen under an electron microscope.
Food Engineering
Fateme Mousavi Baygi; Arash Koocheki; Behrooz Ghorani; Mohebbat Mohebbi
Abstract
Introduction Curcumin, as a natural polyphenolic nutraceutical has been shown many health-promoting effects, mainly associated with its chemical structure. In various studies, different properties of this compound, including anti-tumor and anti-cancer activity, reduction of blood and liver cholesterol ...
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Introduction Curcumin, as a natural polyphenolic nutraceutical has been shown many health-promoting effects, mainly associated with its chemical structure. In various studies, different properties of this compound, including anti-tumor and anti-cancer activity, reduction of blood and liver cholesterol levels, increase of immune function, prevention of cardiovascular diseases, prevention of damage to biological membranes against peroxidation and anti-inflammatory properties have been reported. Despite possessing a potential health benefits to humans, the susceptibility of this polyphenol towards environmental conditions and low chemical stability has restricted the direct usage of curcumin into aqueous-based food formulations. The encapsulation of curcumin in liposomes is a potentially effective way to protect them from degradation during passing the digestive system.Materials and MethodsCurcumin (powder, purity greater than 99%, 368.38 g/mol), lecithin, cholesterol (C3045-25G), pancreacin (extracted from porcine pancreas, P7545-25G), bile salts (B8756-10G) and calcium chloride (CaCl2) was obtained from Sigma Aldrich (USA). Consumable ethanol was purchased from Pars Ethanol Company (96%, Iran). Lipase enzyme (extracted from pig pancreas, L8070) and pepsin (activity 3500-3000 NFU/g, P8390) were obtained from Solarabio (China). Potassium chloride, dipotassium hydrogen phosphate (K2HPO4) and alpha-amylase enzyme with a purity of at least 99% were obtained from Merck, Germany, sodium chloride (NaCl), sodium bicarbonate (NaHCO3) and calcium chloride were obtained from Sigma. The effect of lecithin content (0.02- 0.08 g), lecithin cholesterol ratio (0.5- 4), curcumin level (1.5- 6mg) and ultrasound treatment time (1-5 minutes) on production of liposomes containing curcumin was evaluated. The particle size, particle size distribution, zeta potential and efficiency were determined by response surface methodology. Furthermore, physical nature, molecular structure, physical stability at 4ºC and 25ºC and release behavior of curcumin loaded-liposome in mouth, stomach and intestines were explored.Results and Discussion The results showed that all independent variables had a significant effect on liposome particle size and increasing the ratio of lecithin: cholesterol caused more uniform particle size. Lecithin was determined to be the only component affecting the zeta potential of liposome particles, and increasing the ultrasound time increased the efficiency of curcumin encapsulation in liposomes. The optimal point of liposome preparation conditions in the amount of 0.08 g lecithin, 4: 1 the ratio of lecithin: cholesterol, 4.16 mg curcumin and 5 minutes the ultrasound treatment was introduced by Design Expert software. In addition, curcumin was amorphous in optimal liposome spherical particles. Furthermore, the results of TEM showed that the liposomes are in the form of single-layer particles, spherical and without membrane rupture. This makes the bilayered nature of the vesicles clearly visible in this micrograph. The size of the particles obtained from this method was consistent with the data obtained from the dynamic light scattering method. From the results of infrared spectroscopy, it can be seen that curcumin is trapped in the liposome through hydrogen bonding in the double-layered vesicle of the liposome, the phenolic ring of curcumin with the phospholipid head group, as well as the hydrophobic interactions of the aromatic rings with the acyl phospholipid chains. Liposomes were more stable at refrigeration temperature. A very small amount of curcumin was released in the simulated oral phase, which is probably due to the short time and lack of specific enzymes to disrupt the phospholipid bilayers of the liposome. Although the pepsin enzyme is unable to penetrate the liposome membrane, acidic conditions change the angle of the head and tail groups of the lipids and lead to a change in the surface charge of the liposomes. The release of curcumin from liposome vesicles was greatly increased in the intestine. This sudden increase is due to the presence of bile salts as an emulsifying agent that can disrupt the phospholipid membrane and make the membrane more fluid. In addition, pancreatic lipase is adsorbed on the surface of lipids and then hydrolyzes the phospholipid into 2-acyl and 1-acyl lysophospholipids and free fatty acids. The release behavior of curcumin under gastrointestinal conditions was based on the Fick mechanism.
Food Technology
Farinaz Saremnejad; Mohebbat Mohebbi; Arash Koocheki
Abstract
Introduction: Increasing diet-linked diseases and following that the consumers ongoing desire for healthier foods makes reduced-fat products of outstanding importance in the food industry. This study aims to reduce the fat content of sauces as a traditional condiment through the incorporation ...
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Introduction: Increasing diet-linked diseases and following that the consumers ongoing desire for healthier foods makes reduced-fat products of outstanding importance in the food industry. This study aims to reduce the fat content of sauces as a traditional condiment through the incorporation of air bubbles in the oil phase. Response surface methodology (RSM) was used for identifying the effect of aeration process variables on foam properties. However, the main challenge of reduced-fat foods is to ensure their acceptability. Recently fat taste has been introduced as a sixth basic taste. Fatty acids have been considered as the stimulus for this taste. So, linoleic acid as the stimulus for fat perception was added to the formulation to develop a product that tastes almost like full-fat versions but contains less fat. The advantages of aerated foods over conventional products are clear. Nonetheless, the determination of quality and sensory parameters during storage, marketing, and consuming is necessary. For this purpose, produced aerated sauces, along with commercial full- and reduced-fat sauces, were compared by measuring the acidity, pH, oxidative stability, and sensory properties. Materials and Methods: Required amounts of mono- and diglyceride (MDG) and oil were mixed. Then nonaqueous foams were generated by whipping the MDG-oil mixtures. In the optimization study, the effect of MDG concentrations (2, 6, and 10 wt. %), whipping speed (1100, 3250, and 5400 rpm) and time (5, 15, and 25 min) on foam properties (overrun and drainage) was analyzed using RSM. The foam obtained from the optimum process condition was used to produce an aerated reduced-fat sauce. Sauce preparation was performed according to a usual recipe with the difference that the fat content was replaced by nonaqueous foam. Furthermore, 3.00 mM of linoleic acid as a fat taste stimulus was added to the formulation. First, an aqueous phase containing ingredients was prepared. Then nonaqueous foam was progressively incorporated in the aqueous phase. For the purposes of comparison, aerated sauces (0 and 3.00 mM stimulus), along with commercial sauces (zero, low, and full-fat), were analyzed by measuring the pH, acidity, oxidative stability, and sensory properties. Results and Discussion: According to the results of the optimization study, the desired foam (overrun ≥ 60 %) achieved by oil containing 10 wt. % MDG at 3400 rpm for 10 min. Overrun increased progressively with MDG concentration but decreased slightly above 10 wt. % due to the difficulty of dispersing air bubbles in such a viscous gel. Considering the effect of whipping speed, and time, it was observed that mixtures reached their maximum volumes within 25 min. With a further increase in the whipping rate, the time required to achieve the maximum amount of foam was decreased. However, at high whipping speed (5400 rpm), foam volume decreased rapidly with time, and almost a lot of foam collapsed. The lowest and highest pH was related to zero and full-fat commercial sauces, respectively. There was no difference (p>0.05) between the pH of the control and the linoleic acid containing aerated, as well as low-fat sauces. Over time, as the pH decreases, the acidity of the aerated sauces increased and making the products with appropriate microbial stability. Due to the significant reduction of fat amount, oxidation of the aerated sauces was much slower than the full-fat one (p<0.05). Appearance, taste, and texture characteristics of aerated sauces provided a sensory profile similar to the full-fat sauce. The aerated sauce containing linoleic acid had higher sensory scores, indicating its general acceptance. Conclusions: In this study, nonaqueous foam as a new approach for fat replacement in emulsion-based foods such as sauces was practically applied. The optimum aeration process conditions were determined by the help of experimental design. Two types of aerated sauces were prepared based on the linoleic acid concentration, and their physicochemical and sensory characteristics were compared with commercial sauces. The acidity and pH of the sauces were in the standard range, and also their oxidative stability was acceptable during storage time. Generally, the aerated sauce containing linoleic acid had relatively similar sensory profiles to the full-fat sauce. Therefore, it seems that nonaqueous foam could be used successfully to develop reduced-fat alternative foods, which could also be meet the consumers' and marketing requirements.Materials and Methods: Required amounts of mono- and diglyceride (MDG) and oil were mixed. Then nonaqueous foams were obtained by whipping the MDG-oil mixtures. In the optimization study, the effect of MDG concentration (2, 6, and 10 wt. %), whipping speed (1100, 3250, and 5400 rpm) and time (5, 15, and 25 min) on foam properties (overrun and drainage) were analyzed using RSM. The foam obtained from the optimum process condition was used to produce an aerated reduced-fat sauce. Sauce preparation was performed according to a usual recipe with the difference that the fat content was replaced by nonaqueous foam. Furthermore, 3.00 mM of linoleic acid as a fat taste stimulus was added to the formulation. First, an aqueous phase containing ingredients was prepared. Then nonaqueous foam was progressively incorporated in the aqueous phase. For purposes of comparison, aerated sauces (0 and 3.00 mM stimulus), along with commercial sauces (zero and full-fat), were analyzed by measuring the pH, acidity, oxidative stability, and sensory properties. Results and Discussion: According to the results of the optimization study, the desired foam (overrun ≥ 60 %) achieved by oil containing 10 wt. % MDG at 3200 rpm for 10 min. Overrun increased progressively with MDG concentration but decreased slightly above 10 wt. % due to the difficulty of dispersing air bubbles in such a viscous gel. Considering the effect of whipping speed, and time, it was observed that mixtures reached their maximum volumes within 25 min. With a further increase in the whipping rate, the time required to achieve the maximum amount of foam was decreased. However, at high whipping speed (5400 rpm), foam volume decreased rapidly with time, and almost a lot of foam collapsed. The lowest and highest pH was related to zero and full-fat commercial sauces, respectively. There was no difference between the pH of the control and the linoleic acid containing aerated sauces. Over time, as the pH decreases, the acidity of the aerated sauces increased and making them products with appropriate microbial stability. Due to the significant reduction of fat amount, oxidation of the aerated sauces was much slower than the commercial ones. Appearance, taste, and texture characteristics of aerated sauces provided a sensory profile similar to the full-fat sauce. The aerated sauce containing linoleic acid had higher sensory scores, indicating its general acceptance. Conclusions: In this study, nonaqueous foam as a new approach for fat replacement in emulsion-based foods such as sauces was practically applied. The optimum aeration process conditions were determined by the help of experimental design. Two types of aerated sauces were prepared based on the linoleic acid concentration, and their physicochemical and sensory characteristics were compared with commercial sauces. The acidity and pH of the sauces were in the standard range, and also their oxidative stability was acceptable during storage time. Generally, the aerated sauce containing linoleic acid had relatively similar sensory profiles to the full-fat sauce. Therefore, it seems that nonaqueous foam could be used successfully to create reduced-fat alternative foods, which could also be meet consumers' and marketing requirements.
Food Technology
Morteza Heidarian; Mohammad Goli
Abstract
Introduction: Lifestyle modifications related to change in the eating quality and quantity along with mental stress led to the prevalence of non-communicable diseases. Based on the consumer’s demand, food scientists are now focusing on developing sugar free or low- carbohydrate, fat free, low calorie, ...
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Introduction: Lifestyle modifications related to change in the eating quality and quantity along with mental stress led to the prevalence of non-communicable diseases. Based on the consumer’s demand, food scientists are now focusing on developing sugar free or low- carbohydrate, fat free, low calorie, and fiber and protein rich foods. Masghati is one of the Iranian traditional sweets, which is very popular due to its desirable texture and sensory properties. However, considering its high sugar content, its consumption is restricted in obes and diabetics. In recent years, a number of artificial sweeteners like saccharine, acesulfame‐K, aspartame, which are sweeter than sucrose and nontoxic, have been developed and introduced to replace sugar. One more sweetener, sucralose, has gained the approval of the Food and Agriculture Organization/World Health Organization. Sucralose, the only noncaloric sweetener originated from sugar is approximately 600 times sweeter than sucrose and is marketed for broad use in food and beverages in over 30 countries worldwide. Isomalt is a sweet, low-calorie bulking agent with properties and characteristics similar to sucrose. It is a sugar alcohol that is odorless, crystalline, and non-hygroscopic. The sweetening power of isomalt lies between 0.45 and 0.60 as compared with that of sucrose. Ganoderma lucidum is a wood-degrading mushroom that is treasured as a functional food since primitive times. Ganoderma is a rich source of protein, carbohydrate, fat, fiber and ash. No research has been done on the use of Ganoderma lucidum and substituting sucrose with sucralose-isomalt, as well as substituting wheat starch with potato starch in Masghati formulation, Therefore, the aim of this study was to investigate the possibility of enrichment this product with Ganoderma lucidum and sucrose substitution with sucralose-isomalt and wheat starch substitution with potato starch. Materials and Methods: Materials used in Masghati formulation consisted of wheat and potato starch (Shahdineh Aran Co), isomalt, sucralose, Ganoderma lucidum were supplied from salamatgostaran arayan Co. All chemicals were from Merck Co. The formulation of Masghati include wheat starch (9.34%), sugar (46.72%), oil (9.34), saffron (0.02%), cardamom (1.4%), rosewater (23.36%) and vanilla (0.48%) were selected. To produce Masghati, the mixture of sugar, oil and water was heated to boiling temperature and complete dissolution. After the heat treatment (100°C for 2h), the mixture was cooled to 40°C and the wheat starch was added and mixed. At the end, saffron, cardamom, rosewater and vanilla were added. The prepared mixture was molded and placed at 18°C for 24h. Moisture, protein and sugar were determined according to AOAC (2000) and AACC standard numbers, 46-12 and 01-50-80. The density was also determined according to (Le-Bail et al., 2010). High-performance liquid chromatography measurement of vitamin D was performed according to National institute of standard number 13579. Textural properties were determined using a Texture Analyzer. In this study, the effects of sucrose replacement with sucralose-isomalt (0-100%), wheat starch replacement with potato starch (0-100%) and Ganoderma lucidum (0-1%) on physicochemical and textural properties (density, hardness, adhesiveness, springiness) were investigated by response surface methodology (RSM) in the form of a central composite design with 6 central point (α=2). Optimal and control samples were examined in terms of qualitative characteristics such as moisture, protein, sugar, vitamin D, density, textural (hardness, adhesiveness, springiness, cohesiveness, gumminess, chewiness) and sensory properties during 0, 15, 30 and 45 days after production. Comparison of the optimal and control samples was done in a Duncan's new multiple range test using SPSS ver: 9.1 software. Results and Discussion: The results revealed that increase in the percentage of wheat starch replacement with potato starch and replacing sucrose with sucralose-isomalt in higher amounts resulted in an increase of the density. The variables of sucrose substitution with sucralose-isomalt and wheat starch with potato starch at the assessed levels did not have a significant effect on the adhesiveness and springiness of the produced samples. The interaction effect of sucrose substitution with sucralose-isomalt and wheat starch with potato starch showed that, in 75% level of wheat starch substitution with potato starch and 25% sucrose substitution with sucralose-isomalt had a significant effect on reducing hardness and softening samples. Treatments obtained by the model contain 62% sucrose substitution with sucralose-isomalt , 40% wheat starch substitution with potato starch and 0.46% Ganoderma lucidum and 52% sucrose substitution with sucralose-isomalt, 36% wheat starch substitution with potato starch and 0.53% Ganoderma lucidum, were introduced as optimal samples to maintain the quality characteristics and increase Masghati nutritional value. Considering the results, substitution a part of the sucrose with sucralose-isomalt and using Ganoderma lucidum in Masghati formulation led to a successful reduction of total sucrose, and an increment of protein and vitamin D.
Food Technology
Zahra Kholoosi; Mostafa Mazaheri Tehrani; Seyed Mohammad Ali Razavi
Abstract
Introduction: Proteins and polysaccharides are natural biopolymers that consider among the most widely used hydrocolloids in the food industry (Gaonkar and McPherson 2006) Which are often used simultaneously to improve functional properties. In electrostatic interaction, positively charged proteins with ...
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Introduction: Proteins and polysaccharides are natural biopolymers that consider among the most widely used hydrocolloids in the food industry (Gaonkar and McPherson 2006) Which are often used simultaneously to improve functional properties. In electrostatic interaction, positively charged proteins with polysaccharides containing negative groups below the protein isoelectric point (PI) (LEE, MORR, and HA 1992), Leads to the formation of macromolecular particles by creating molecular aggregates rich in biopolymers suspended in the aqueous phase, called complex coacervate, which cause the coagulation and spontaneous separation of the phase. The ratio of protein-polysaccharide biopolymers and the pH of the mixture are important factors influencing the adsorption and compatibility of protein- polysaccharides as well as the characteristics of their aggregates (Shu et al. 1996). For this purpose, the optical density (turbidity) of protein-polysaccharide mixtures and the yield of dried sediments in this study as a basis for optimizing the complex coacervate process as in previous studies (Wang, Adhikari, and Barrow 2014; Huang et al. 2012) were used. In the present study, the optimization of complex coacervate formation conditions of whey protein concentrate-cress seed gum as well as the foaming properties of complex coacervate were studied for the first time. Whey proteins, as amphiphilic macromolecules, can adsorb at the interface (Scheer, Kruppke, and Heib 2001; Tamm et al. 2012; Wierenga and Gruppen, 2010) and form a viscoelastic adsorbent layer (Wilde 2000). Also, whey protein acts as a foaming agent with the ability to be adsorbed at the joint water-oil and water-air interface through hydrophobic interactions or disulfide bridges, and intermolecular bonds (Nicorescu et al. 2008; Nicorescu et al., 2008; Dickinson, 1992; Forschen, 2017). Cress seed gum has rheological, emulsifying, favorable foaming properties and is stable in a wide range of heat, cold, salt, and pH with synergistic effects in the presence of sugars (sucrose, lactose). These properties are important in stabilizing emulsions and foams. The general purpose of this study was to achieve the optimal point of electrostatic interaction of different ratios of whey protein concentrate with cress seed gum in the pH range of 2 to 7 using response surface methodology and to investigate the foaming properties of the coacervate complex at the optimal point in comparison with Pure control protein in the same ratio. Materials and Methods: The raw materials of this study included cress seed, whey protein concentrate with 80% purity (from Milli com., Germany), and hydrochloric acid with 37% purity (from Merck Com.). Different protein-polysaccharide mixtures were prepared to optimize the electrostatic interaction with the ratio of biopolymers (1: 5 to 5: 1 w / w) and pH of interaction (2 to 7). Mixtures, in the ratio determined by the software and the total concentration of biopolymer (0.3%), were prepared, and after 15 minutes of stirring and equilibration with the environment, were adjusted by hydrochloric acid of 0.1, 0.5, and 1 (n) to the desired pH, and stirred for 5 minutes at each pH with a magnetic stirrer at 400 rpm. Optical Density (OD) of protein: polysaccharide mixtures was evaluated by visible-ultraviolet optical spectrophotometry (Unico, Model S-2150, USA). To optimize the electrostatic complex coacervation process, the coacervation yield was determined. The result of the interaction of whey protein concentrate and cress seed gum as a function of pH and protein to gum ratio was investigated by measuring the sediment phase. For investigation of the foaming properties, the dispersions were homogenized using a homogenizer (Ultra Turrax T25 Digital) for 5 minutes at a speed of 10,000 rpm. After recording the sample volume in the dimension and before homogeneity, the foaming capacity was calculated. To determine the stability of the foam, changes in the volume of the samples were recorded and calculated after 30 minutes of foaming. In this study, the effect of two independent variables including the ratio of biopolymers in the range of 0.2-5 (w/w) and the pH within the range of 2 to 7 were analyzed using Design-Expert software based on two responses including turbidity and yield by the combined central design (CCD) with 5 replications to optimize the electrostatic interaction of whey protein concentrate with cress seed gum.Results and Discussion: The results obtained by using response surface methodology showed that the independent variables (ratio of whey protein to cress seed gum and pH) in this study affected the studied responses (turbidity and sediment percentage), although pH had the greatest effect. Optimal conditions for the formation of the maximum protein-polysaccharide coacervate complex were obtained in the ratio of protein to polysaccharide 5: 1 (w / w) and pH 4.24. The results of foaming properties at the optimal point showed an increase in foaming capacity and foam stability compared to pure protein (control sample). This increase in foaming properties is probably due to the presence of cress seed gum and its effect on the formation of a thick viscoelastic film, improved protein adsorption at the interface, and increased bulk phase viscosity.
Food Engineering
Fatemeh Karani; Javad Sargolzaei
Abstract
Introduction: The Okra belongs to the family Malvaceae with the scientific name Abelmoschus esculentus (Peyvast, 2009). The viscous property of okra is due to the thick and viscous matter in the fruit pod, called mucilage. Okra mucilage is a polysaccharide currently used in pharmaceutical industry as ...
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Introduction: The Okra belongs to the family Malvaceae with the scientific name Abelmoschus esculentus (Peyvast, 2009). The viscous property of okra is due to the thick and viscous matter in the fruit pod, called mucilage. Okra mucilage is a polysaccharide currently used in pharmaceutical industry as a hydrophilic polymer in tablet coatings (Bakre et al, 2009). Mucilage collectively contains polysaccharides, proteins, and minerals found in a plants or seeds that are more widely used in various industries, including food industry, as a stiffener in dairy products. Mucilage composed of monosaccharide polymers, amorphous and semi-transparent, and are hydrocolloids. These materials are hydrophilic molecules that can be extracted with water and form a concentrated or gel solutions. Gels are widely used in the food, pharmaceutical and non-pharmaceutical industries. The cultivation of okra in Iran is mainly occurred in tropical and subtropical regions and is found in Khuzestan, Ilam, Kermanshah, South Fars, Bushehr and Hormozgan provinces (Mozafarian, 2012). Many studies have been done on the extraction of okra mucilage and its applications in the pharmaceutical and food industries. Faroq et al. worked on the organoleptic properties of okra mucilage and concluded that okra mucilage has good flow properties and high solubility in water that can be used safely without any side effects (Farooq et al, 2013). ). Noorlaila et al studied the emulsifying property of mucilage extracted from okra (Noorlaila et al, 2014). Nazni and Vigneshwar studied the extraction and evaluation of organoleptic properties of mucilage from okra and several other plants and used ethanol and acetone to purify mucilage (Nazni et al, 2012). A study was conducted in 2018 to study the basic properties such as swelling index, emulsion stability, viscosity and antioxidant activity of okra mucilage (Fekadu Gememde et al, 2018). In a study on the use of okra mucilage in pharmacy, Ameena et al after extracting mucilage from okra and measured the physicochemical properties of mucilage, applied it in tablet formulation and many parameters such as diameter, thickness, weight change, hardness and Fragility were assessed. According to observations, low concentrations of okra mucilage can be used as a substitute for starch in tablet formulation, and also high levels of okra mucilage can be used in the drug release system as a natural substance (Ameena et al, 2010). In a study, Mishra et al presented okra mucilage as a new proposal to replace polymer materials used in various industries (Mishra et al, 2008). In 2014, the effect of okra mucilage on the release of propranolol hydrocolloid in tablets was studied. The highest hardness and lowest brittleness were observed for okra tablets (Zaharuddin et al, 2014). In this research, extraction of okra mucilage was investigated by two methods of solvent and supercritical fluid extraction. Optimization the yield and physicochemical properties of the extract obtained from both methods was also investigated. Materials and methods: Fresh okra obtained from local supermarket in Khuzestan province. Chemicals materials such as pure ethanol, acetone, chloroform, acetonitrile purchased from Merck and Sigma Aldrich. After transferring the okra fruit to the laboratory, the contaminants were removed from the plant and then rinsed thoroughly with water. The okra pods were dried at about 40 °C in a digital fan oven model 6882A. It was powdered by a German-made electric milling machine and then it passed through a 30-mesh sieve to be ready for extraction and it was weighted by laboratory scales (0.0001 precision manufactured by Cornell, Germany). In the solvent extraction process, the okra powder was weighed by a digital balanced (GR-200 model made in Japan) and transferred to 250 ml human. The solids stirred in distilled water and various amounts of solvent for 1 to 5 hours until the mucilage is completely released into the water. The solution was filtered and then adjacent to an organic solvent. Then, the filtrate was poured again into Petri dish and placed on a water bath at 45 °C to evaporate the residual solvent inside it. The residue inside the Petri dish was dried in a fan oven (Reyhan Teb Company) at 40 °C and powdered and kept at 20 °C until the day of analysis. In the supercritical extraction method, the supercritical fluid extraction machine which designed and manufactured in the laboratory of the Faculty of Engineering at Ferdowsi University of Mashhad was used. The carbon dioxide was supplied by Khakakan Co., Quchan Road, Iran in a 45 kg cylinder. Results & Discussion: Generally, according to the results of both methods of solvent extraction and supercritical fluid extraction (SFE), the extraction efficiency of mucilage at the optimal point in the solvent extraction and in the supercritical methods was 5.12% and 1.58%, respectively. Due to the less use of organic solvents in the supercritical method, this method is more environmentally friendly, which is significant in converting the laboratory method to pilot or industrial scale. Physio-chemical analysis of mucilage obtained by two methods shows that the index of swelling, moisture and ash of mucilage obtained by maceration is more than that of supercritical mucilage. By comparing the obtained values at the optimal point of both methods, the solvent method has a higher total efficiency and has been more successful. However, in the supercritical fluid method, the solvent utilization is significantly reduced. The extraction time in the supercritical fluid method is also reduced by about 50%.
Masoud Hafiz; Zahra Sheikholeslami
Abstract
Introductıon: In baked foods, hydrocolloids have been used for retarding staling and improving the quality of fresh products ((Ba´rcenas et al 2003, 2004). Researchers found that all hydrocolloids are able to hold moisture loss during crumbing of bread and reduce the rate of water loss and moisture ...
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Introductıon: In baked foods, hydrocolloids have been used for retarding staling and improving the quality of fresh products ((Ba´rcenas et al 2003, 2004). Researchers found that all hydrocolloids are able to hold moisture loss during crumbing of bread and reduce the rate of water loss and moisture to increase the bread crumb (Arendt, 2013). Ocimum basilicum L., and Amygdalus scoparia., commonly known as Basil and Farsi gums, are a good source for pharmaceutical, food and industrial applications. The aim of this study was to evaluate the effect of Ocimum Bacilicum and Farsi gums on optimization of loaf bread production by decreasing the hardness and increasing the special volume, porosity and extensibility values by using the response surface method. Materials and methods: The Ocimum bacilicum seeds were first cleaned, then seeds were soaked in distilled water to obtain a water to seed ratio of 37:1 at 40 ˚C and pH = 7. Separation of the hydrocolloid from the swollen seeds was achieved by passing the seeds through an extractor equipped with a rotating plate that scraped the gum layer on the seed surface. The extracted solution was then filtered and dried in an air forced oven at 60˚C and finally the powder was milled, sieved using a mesh 18 sifter, packed and kept at cool and dry condition (Karazhiyan et al., 2010, Mohamad Amini et al., 2007). Farsi gum in powder were bought from Rihan gum Parsian co. The effect of Basil and Farsi seed gum concentration (0-1%) on water activity, moisture, specific volume, hardness and extensibility of bread was investigated. For Data Analysis used SPSS software and Duncan test, for mean comparisons. Results and discusions: The results revealed that the water activity in bread was decreased while an enhancement was observed in moisture, hardness and extensibility with an increase at gum concentration. Further, the specific volume and porosity of bread were increased and then decreased by adding the gum with higher level. In order to reach to a minimum hardness and maximum specific volume, porosity and extensibility, the concentration of Basil and Farsi seed gum should be 0.46 and 0.35% respectively. The results of this study showed that any increase in concentration of gum in the formulation, makes moisture content, hardness and elongation to be increased, but the activity of water decreased. However, with the increase of Farsi gum, the amount of specific volume and porosity increased and then decreased. In the end, it can be stated that, in order to obtain optimal conditions for bread formulation, the percentage of basil and Farsi gum seeds should be 0.42 and 0.35% respectively.
Mitra Mansouri Bani; Vahid Samavati; Marzieh Bolandi
Abstract
Introduction: The Cholesterol in our diet is a risk factor for the prevalence of cardiovascular diseases. One of the effective ways to reduce the incidence of such diseases is to remove cholesterol, including animal fats, from our food sources. In this research, attempts were made to investigate the ...
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Introduction: The Cholesterol in our diet is a risk factor for the prevalence of cardiovascular diseases. One of the effective ways to reduce the incidence of such diseases is to remove cholesterol, including animal fats, from our food sources. In this research, attempts were made to investigate the effect of operational factors on reducing cholesterol in cream by beta-cyclodextrin using RSM and to examine its physicochemical properties. The variables in this study were beta-cyclodextrin concentration, mixing temperature and mixing time. Materials and Methods: The 3.5% fat raw milk was pasteurized at 72°C for 16 s, and then it was cooled to 55°C. The milk cream was separated by a separator and adjusted to 36% fat. Beta-cyclodextrin was added in 0.5, 1, 1.5% concentration in water bath at three levels of 10, 30, 50 ° C. It was mixed at three time intervals of 5, 15, 25, min. Cream containing beta-cyclodextrin was centrifuged to eliminate the complex formed in different periods and the beta-cyclodextrin and cholesterol complex was isolated. Beta-cyclodextrin of 99.2% purity was purchased from Sigma-Aldrich and all chemical agents from Merk, Germany. To measure cholesterol content in the preparation phase, hexane and ethanolic solution of potassium hydroxide (Merk) and the standard solution of cholesterol (Merk) were used. To determine the level of cholesterol in the samples, Lee et al. (1999) method was used after a few modifications. Firstly, cholesterol was extracted from the specimens and the cholesterol levels in the samples were determined with a chromatography apparatus equipped with flame ionization. The quantitative measurement of cholesterol was conducted by comparing the peak areas with a response from the internal standard. The experiments were designed, using the response surface method and the Box-Behnken Design (BBD), to achieve a high-efficiency process in reducing the highest cholesterol level and determining optimum conditions. The viscosity was determined using a Brookfield viscometer, and the over run and foam stability of the cholesterol cream samples were determined using a Graduated cylinder. Results and discussion: Due to the cavity in the central part of beta-cyclodextrin molecular arrangement, it can form a stable cholesterol-insoluble complex and help to isolate it from the product. The results showed that time, mixing temperature, and beta-cyclodextrin concentration all had a positive effect on reducing the level of cholesterol, and the effect of independent factors was almost the same, as the time factor had the highest effect, supported in Makoto et al. (1999). Concentration factor had the least effect on cholesterol reduction, contrary to studies by Aryafar et al. (2007) and Yen et al. (1995). Among the interactions of the investigated factors, the highest effect was due to the simultaneous effects of temperature and time (88.9%) and the least effect was due to the simultaneous effect of concentration and temperature (85.5%). Findings of this study showed that the use of beta-cyclodextrin resulted in a successful reduction of cholesterol from the product without affecting tissue properties, increasing viscosity and volume, or reducing stability of the foam. The absorption of cholesterol by beta-cyclosporine depends on its concentration. The mixing time and temperature also boosts the effect. After examining the effects of each independent variable, it can be concluded that all three investigated variables have an incremental effect on the level of cholesterol in the evaluated levels. Increasing mixing time has the highest effect on increasing cholesterol and increasing the concentration of beta-cyclodextrin has the lowest effect on cholesterol reduction. Investigating the interaction effects of variables also showed that the simultaneous effect of temperature and time with the proper concentration of beta-cyclodextrin could have a significant effect on cholesterol reduction. The response surface method and Box-Behnken Design as statistical optimization and modeling techniques enabled the researchers to predict the optimal conditions for maximal removal of cholesterol by beta-cyclodextrin at the decided levels. The optimal operating condition obtained by the model for 36% fat cream contains 42.1% beta-cyclodextrin concentration, 76.75 ° C temperature and 87.83 min of mixing time. The predicted cholesterol reduction in these conditions was 89.92%, which was very close to the experimental value obtained in predicted optimal conditions. It indicates the accuracy and predictive power of the intended model.
Manoochehr Rashidi; Reza Amiri Chayjan; Ali Ghasemi
Abstract
Introduction: Tomato is one of the most valuable sources of minerals and vitamins supply in the human diet. Low shelf life of tomato and its short shelf life with inadequate processing facilities lead to heavy financial losses. Therefore, preserving and processing of tomato are of the commercial importance. ...
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Introduction: Tomato is one of the most valuable sources of minerals and vitamins supply in the human diet. Low shelf life of tomato and its short shelf life with inadequate processing facilities lead to heavy financial losses. Therefore, preserving and processing of tomato are of the commercial importance. Drying is one of the preferred methods for tomato preservation. Dried tomato products including half tomatoes, tomato slices and tomato powder, have many consumptions, compared with other tomato products. Among dried tomato products, tomato powder has a particular market. Powder production is an alternative method to extend the shelf life of foods. Usually the fruit powder is very dry, humidity absorber and has too much volume. Therefore, during storage, transportation and administration, it requires special care and heavy packaging which increase the cost. To overcome these problems, compression of the fruit powder in tablet form could be a proper solution. Tablet making of fruit powder has gained much popularity due to its ease of use, storage, transportation and product formulation. After the tablet making process, the pills contain high moisture contentwhich makes them un-suitable for transportation and storage. So, in order to prevent the tablets corruption and maintain their quality, tablet drying is one of the important steps after the tablet making process. The drying process is an important operation that affects the quality and final price of the product. Different drying methods play an important role in protecting foodstuffs. However, the effect of different drying methods on the quality of some foodstuffs is not clear. Materials and methods: In this research, after the preparation of fresh tomatoes, the primary moisture content of tomatoes was determined using hot air oven method. Then, using blanching method, the tomatoes were peeled and samples were cut using a sharp razor in thicknesses of 3 mm. Tomato slices were dried using a semi-industrial dryer in a hot air at 50 °C at an air speed of 1 m/s. Dried tomato slices were powdered using a grinder. In order to homogenize the particle size, the tomato powder was sieved by a 50 mesh (Cavity size 0.5 mm) sample. Suitable moisture content to create sufficient adhesion between the particles of tomato powder was selected at %23 d.b. Water and fructose were used as a bonding agent. The process of producing tomato spherical tablets was performed by a hydraulic press. Drying tests of wet compressed tablets were performed immediately after the end of the tabletting process using a hot air drying machine with microwave pre-treatment. In this study, the effect of drying variables,through using of microwave pre-treatment along with hot air, including air temperature in five levels (40, 50, 60, 70 and 80 °C), air velocity at five levels (0.5, 1, 1.5, 2, and 2.5 m/s) and the duration of microwave application at five levels (zero (without microwave), 4, 8, 12, and 16 s) on physical properties (shrinkage and unit density), mechanical (penetration resistance) and thermal (Effective moisture diffusivity and energy consuming drying) of compact pomegranate produced from tomato powder were studied. Statistical analysis of data and optimization of drying process were performed using response surface method and central composite design. Results and discussion: Results showed that effect of air temperature and duration of microwave pretreatment on all variables of compressed tomato tablets were significant in hot air dryers with microwave pre-treatment. Increasing temperature and time of microwave pre-treatment increased the effective moisture diffusivity and shrinkage of the final product. The temperature of the air inlet to the dryer had a negative effect on the resistance to penetration, the unit density and the specific energy consumption of the drying process. Drying under lower temperature conditions and less time for microwave pre-treatment resulted in an increase in the desirability of the drying process
Elnaz Shafie; Mohammad Goli
Abstract
Introduction: Milk dessert is a product that contains at least 50% the fresh cow milk or reconstituted milk, which is made with supplementary additives such as flavors, sweeteners, thickeners, and stabilizers, after undergoing heat treatment such as pasteurization or sterilization. Spirulina platensis ...
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Introduction: Milk dessert is a product that contains at least 50% the fresh cow milk or reconstituted milk, which is made with supplementary additives such as flavors, sweeteners, thickeners, and stabilizers, after undergoing heat treatment such as pasteurization or sterilization. Spirulina platensis is a multi-cellular microalgae and a green-blue filament that is a rich source of protein, essential amino acids, essential fatty acids, vitamins, minerals and pigments. Today, as a substitute for sucrose, non-caloric sweeteners are used, which in a small amount make too much sweetness, but they are not absorbed by the body. Of these, stevia with higher sweetness than sucrose (300 to 400 times), less calories and lower glycemia index, is a good herbal sweetener to replace sucrose. Materials and methods: Factor A contains the percentage of algae Spirulina platensis (alternative to milk powder) at 5 levels (0-2 % of the final formula), factor B contains the percentage of stevia replacement with sucrose at 5 levels (0-100), to achieve optimal pudding production formula were selected. Optimization of formula was performed based on the parameters of syneresis, viscosity, hardness and cohesiveness by Response Surface Method (central composite design, α=2 with 6 central points). The results were analyzed using SPSS 20 software and the comparison of the means was done by LSD at 5% level and the charts were drawn by Excel software. Results & Discussion SyneresisGenerally, due to the increase of molecular connections between the chains and the outflow of water from the structure is created. According to the results of Table 3, the independent effect of stevia replacement with sugar, the interaction effect of Spirulina platensis and stevia replacement, and the quadratic effect of each of the independent variables on the Syneresis factor were significant (P <0.05). The rate of syneresis of the samples at higher levels of stevia replacement was reduced by decreasing the percentage of Spirulina platensis replacement, and at lower levels of stevia replacement, with the decrease in the percentage of Spirulina platensis replacement, the amount of syneresis significantly increased. Water holding capacity is linked to the ability of proteins, fats, and dietary fiber to maintain water inside the product structure. Because Spirulina platensis has high levels of protein, dietary fiber and fat, its presence in the formulation of frozen desserts has a significant effect on reducing the product's syneresis. ViscosityAs shown in Table 3, the independent effect of Spirulina platensis replacement and stevia replacement, the interaction effect of Spirulina platensis and stevia replacement, the quadratic effect of Spirulina platensis and stevia replacement on the amount of viscosity was significant (P <0.05 ). The level of viscosity at lower levels of stevia replacement decreased with a decreasing percentage of Spirulina platensis replacement, and at the higher levels of stevia replacement, reducing Spirulina platensis replacement percentage was no significant effect on the viscosity (Fig. 2). In general, the presence of Spirulina platensis in the pudding formulation increased its viscosity, which could be due to the Spirulina platensis protein structure and intercellular interactions. Spirulina with high water absorption reduces water mobility. Also, the presence of fiber and hydroxyl compounds in the structure of this fine algae has a significant effect on the viscosity of the product. Hardness and cohesivenessReplacement of Spirulina platensis and Stevia in pudding formulations did not have a significant effect on the hardness and cohesiveness of texture. While the interaction effect of Spirulina platensis and Stevia replacement on the hardness and cohesiveness of the pudding samples was significant (P<0.001). The quadratic effect of Spirulina platensis and stevia replacement on the amount of hardness and cohesiveness of texture was significant (P <0.05). At lower levels of stevia replacement, by increasing the Spirulina platensis replacement percentage, the hardness of the samples first increased and then decreased, while at higher levels of stevia replacement, with increasing Spirulina platensis replacement percentage, the hardness of the samples first decreased and then increased. Large particles of Spirulina platensis can cause unconnectedness and network connectivity and ultimately create a more sophisticated structure. In fact, Spirulina platensis protein molecules, having a hydrophilic property, compete with other molecules to bind to water molecules, which results in a weaker and more unstable gel structure. On the other hand, tissue hardness is largely dependent on dry matter, the amount and type of protein in the sample. High levels of protein cause cross-linking in the gel network and, ultimately, a rigid and dense structure. But it should be noted that the amount of sample fat plays an important role in the product's texture. Since Spirulina platensis, in addition to protein, also has significant amounts of fat, the intervention of the fatty molecules of this small algae can be effective in forming a weaker gel network and producing soft texture in the product. Finally, optimal formula 1 (2 % Spirulina platensis and 95% Stevia replacement) and optimal formula 2 (0.1% Spirulina platensis and 50% Stevia replacement) were predicted.
Mohammad Amin Mehrnia; Hassan Barzegar; Leila Hagh jou
Abstract
Central composite design response surface methodology was used to optimize polysaccharide extraction from olive leaves. Effect of three independent variables [extraction time (3- 7 hours), extraction temperature (60- 100°C) and water-to-raw material ratio (5-25 mL/g)] on extraction yield were studied. ...
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Central composite design response surface methodology was used to optimize polysaccharide extraction from olive leaves. Effect of three independent variables [extraction time (3- 7 hours), extraction temperature (60- 100°C) and water-to-raw material ratio (5-25 mL/g)] on extraction yield were studied. Extracted polysaccharide was evaluated for antioxidant properties, total phenolic and flavonoid content and its structure and functional groups were studied using FTIR. Rheological properties and flow behavior of polysaccharide were determined by fitting to power law model. The most important parameter in experimental ranges was temperature and the lowest effect was seen in extraction time. Highest extraction yield was obtained at extraction time of 2 hours, extraction temperature of 80.96°C and water-to-raw material ratio of 17.94 mL/g. Antioxidant properties of extracted polysaccharide were measured using DPPH radical at 517 nm that showed notable antioxidant properties. Rheological property of extracted polysaccharide was studied at 1, 2.5 and 5% concentration. Results showed that at high concentration, polysaccharide shows shear thinning behavior. One of the most important obstacles in native polysaccharide applications is their extraction yield. Extract of olive leaf polysaccharide is highly affected by extraction temperature. Extracted polysaccharide showed good antioxidant properties comparing to BHT and phenolic extract of olive leaf. Moreover it could be used for increasing solution viscosity at higher concentrations.
Fatemeh Farzaneh Moghaddam; Javad Sargolzaei; Shadi Bolourian
Abstract
Introduction: The term antioxidant is said to be compounds that are delaying or preventing oxidization of a substance at their own presence, which leads to reach a stabilized food quality (Collins, 2005). Natural antioxidants are often phenolic compounds that exist in all parts of a plant. These compounds ...
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Introduction: The term antioxidant is said to be compounds that are delaying or preventing oxidization of a substance at their own presence, which leads to reach a stabilized food quality (Collins, 2005). Natural antioxidants are often phenolic compounds that exist in all parts of a plant. These compounds are secondary metabolites that can inhibit active oxygen species by giving hydrogen atoms and converting them into more stable non-radical compounds due to oxidation and reduction properties. They also have the ability to chelate the metals (Wijngaard et al., 2009 and Erasto et al., 2007). Regarding the positive effects of natural antioxidants, many studies have been conducted to extract, identify and apply them from various herbal sources. Edible fruit jujube is a member of the Ramanaceae family, known in Iran as the jujube. The plants of the family are jujube flowers, which are all diploid and have 24 chromosomes. The jujube tree has been cultivated in China for thousands of years ago and is used as a medicine, food and food flavoring, also distributed in tropical and subtropical regions of Europe, Australia and South Asia. (Su et. al., 2005, Yan et. al., 2002, Preeti et al. 2014). Phenolic compounds have a high potential for antioxidants and a natural source of antioxidants. The antioxidant capacity of the Jujube is due to its antioxidant compounds such as flavonoids, total phenolic, anthocyanins and ascorbic acid. Zhao et al., 2014) and Zhang et al., 2010). Shell, pulp and fruit jujube seeds have a wide range of phenolic compounds and have long been used as a drug and flavor agent (Zhang et. al., 2010, Mahajan et al., 2009). Many studies have investigated the effects of Jujube fruit and its juice on the prevention and treatment of diseases such as digestive disorders, weakness, obesity, liver problems, diabetes, skin infections, Infections, Anemia, and Allergies have been reported (Gao et al., 2015 and 2013, Kim et al., 2011, Verma, 2016, Li et al., 2012). In a study by Wang et al. on Jujube fruit, 22 compounds were identified in ethanol jujube extracts (Wang et al., 2014). Zhang et al. The study that they carried out showed that the antioxidant activity of the jujube is due to its antioxidant compounds, such as flavonoids, total phenolic, anthocyanidins and ascorbic acid (Zhang et al., 2010). Italian scientists influence the phenolic compounds of jujube fruit extract on breast cancer cells (Plastina et al., 2012). During a study conducted in Egypt, the effect of jujube fruit on obesity, lipid profile and liver function were examined. (Mostafa et al., 2013). In another study on juvenile fruit phenolic compounds, the effect of jujube on seizure treatment was evaluated and the results showed that jujube has protective properties against seizure, oxidative stress and other disorders. Pahuja et al., 2011).In this research, extraction of phenolic compounds of Ziziphus Jujuba extracts has been performed using the supercritical carbon dioxide fluid method and optimization of the extracted compounds and the measurement of the antioxidant activity of Jujube fruit. Materials and methods: Jujube fruit was prepared from Birjand in late August. Chemical materials such as pure ethanol, reagent Folin-Cictalto, sodium carbonate and free radical molecules from German-German corporations and Sigma Aldrich, and laboratory glassware and instruments such as volumetric balloons, refrigerators and freezers, spatula, vertex, buret, pipettes, calibrated cylinders, Filter paper, Falcon, Human Dimension, Mesh 30, Funnel and Arlene were provided. The freshly purchased fruits were separated from the tree before drying. After separating the jujube grain, the fruit was dried at 40°C in a digital-powered oven (volume 5 liters made by Binder Company in Germany), and dried with the aid of a home-made mill. For particles of uniform size, the resulting powder was sown using a mesh 30 and kept in a refrigerator at -20°C until it was extracted. Results & discussion: Generally, according to the results of both solvent extraction and supercritical fluid extraction (SFE) methods, the total amount of phenolic extraction at the optimal point in terms of mg Gallic acid to gram of dry extract in the solvent extraction and in the supercritical method were 26.21 and 2.24, respectively. Comparison of the obtained values at the optimal point of both methods indicated that the solvent method shows higher values of the total phenol content and it has been more successful. However, due to the insignificant differences in total extraction phenol content between the two methods, the supercritical method can be described as a better way to extract phenolic compounds, since the supercritical method was less effective than antioxidant power despite the presence of phenol, because in the supercritical method, the selectivity can be increased and the target compounds can be isolated by adjusting the temperature and pressure which increases the purity and increase the antioxidant property, and the purpose of the extraction of phenolic compounds. On the other hand, due to the low amount of organic solvent used in this method and the reduction of health and environmental risks, the supercritical method can be introduced as an effective method for extraction of phenolic compounds from Ziziphus Jujube fruit, which reduces the consumption of organic solvent and causes in an efficiency equal with solvent method approximately. In general, according to the amount of total phenolic extraction in both methods, it can be said that Jujube has higher phenol content than other herbs and it can be introduced as a natural antioxidant at the commercial level.
Fatemeh Saadat; Seyed Hadi Razavi; Houshang Alizadeh
Abstract
Introduction: Oil plants store energy in the form of neutral lipids in the organelles called oil bodies. These organelles save triacylglycerol until seed germination. In recent years, the oil bodies have been considered as an oil/water emulsion in the pharmaceutical, food, and cosmetic industries. These ...
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Introduction: Oil plants store energy in the form of neutral lipids in the organelles called oil bodies. These organelles save triacylglycerol until seed germination. In recent years, the oil bodies have been considered as an oil/water emulsion in the pharmaceutical, food, and cosmetic industries. These organelles are also effective tool for purifying, stabilizing and delivery of biotechnology products. Aqueous extraction processing (AEP) is the most common method for oil body extraction. Despite all advantages compared to organic solvent extraction, the yield of AEP still needs to be optimized. Therefore, this study surveys the efficacy of two solvents, phosphate buffer and distilled water in the oil bodies' extraction from rapeseed. Materials and methods: Brassica napus L. seeds were obtained from seed and plant improvement institute, Iran. To compare the efficacy of solvents, 0.1 M phosphate buffer (pH 7.5) and distilled water were used for extraction. The ground rapeseed was suspended in the buffers in a ratio of 1:10 (w/v) and stirred for 12 hours at room temperature. This step was repeated three times. Then, the extract was centrifuged at 10,000 g for 15 minutes at 4 ° C. The floating layer was carefully removed and dissolved again in the initial solvent and the pH was adjusted to 8.5 to precipitate the deflated proteins. Finally, the cream layer was retrieved using centrifuges and one-tenth of the initial buffer volume was applied to the 9 M urea buffer (pH 7.5) for 10 minutes to separate non-specific proteins from oil bodies. The purified oil-bodies were monitored under light microscopy. Results and discussion: According to the microscopic and macroscopic results, the stability of oil particles and efficiency of extraction would be higher by phosphate buffer due to maintaining a constant alkaline pH during the extraction. Moreover, the presence of different salts in the phosphate buffer increases the purification yield up to twice times as a result of providing osmotic pressure and increasing solubility of membrane proteins. These results emphasize the importance of membrane proteins on the formation and stabilization of oil bodies.
Fereshteh Hosseini; Zeynab Raftani Amiri
Abstract
In this study, the effect of stevia (0-0.04 g/100g) as a sucrose replacer, milk protein concentrate (mpc) (0-4 g/100g), and modified waxy corn starch (0-3 g/100g) as fat replacers on the physico-chemical and sensory characteristics of 15% fat cream were analyzed using a central composite rotatable design. ...
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In this study, the effect of stevia (0-0.04 g/100g) as a sucrose replacer, milk protein concentrate (mpc) (0-4 g/100g), and modified waxy corn starch (0-3 g/100g) as fat replacers on the physico-chemical and sensory characteristics of 15% fat cream were analyzed using a central composite rotatable design. Response surface methodology was used for optimization of low calorie cream formulation. Results showed that an increase in sucrose substitution with stevia and mpc concentration was followed by an increase in cream acidity, while pH decreased. Increasing sucrose substitution with stevia in cream decreased firmness, apparent viscosity and consistency, whereas increasing concentration of milk protein concentrate and modified starch increased the cream firmness, apparent viscosity and consistency. However, according to multiple response optimization, the optimum levels of 0.034 g/100g stevia, 1.64 g/100g mpc and 2.30 g/100g modified starch predicted acidity 0.15% acid lactic, pH 6.5, firmness 1.4 N, apparent viscosity 28730.3 mPa.s and consistency 0.52 cm/30 s. The calorie value of formulated cream was 46.44% less than the control sample (cream with 30% fat and 12% sucrose), and no significant difference in total acceptance between them was found, while formulated cream had higher score for taste and creamy state.
Somayeh Niknia; Seyed Mohammad Ali Razavi; Mehdi Varidi
Abstract
In this study, sodium caseinate was hydrolyzed with Withania coagulans extract and the response surface methodology (RSM) was applied to optimize the effects of hydrolysis conditions including hydrolysis temperature, enzyme concentration and hydrolysis time on the degree of hydrolysis, solubility, and ...
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In this study, sodium caseinate was hydrolyzed with Withania coagulans extract and the response surface methodology (RSM) was applied to optimize the effects of hydrolysis conditions including hydrolysis temperature, enzyme concentration and hydrolysis time on the degree of hydrolysis, solubility, and foaming properties. The analysis of variance in RSM showed that the linear effects of enzyme level and hydrolysis time and quadratic effects of hydrolysis temperature were important factors affecting the hydrolysis process remarkably (P<0.0001). Results were indicative of the fact that the increase in responses was obtained by an increase in hydrolysis time and enzyme level. The generated quadratic model showed that the optimum conditions for maximizing the responses were when enzyme concentration of 1.75 (%w/w), temperature of 55.43°C and hydrolysis time of 490 min.
Atefeh Pourmahdi; Mohebbat Mohebbi; Ashraf Gohari Ardabili; Mehdi Varidi; Mohammad Reza Salahi
Abstract
Introduction: Potato is one of the most consumed and highly nutritious vegetables with high energy, dietary fiber, phytochemicals, vitamins, and minerals which offer great benefit for utilization as functional food ingredient. The dried potato powder can be used in formulation of many foods like soups, ...
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Introduction: Potato is one of the most consumed and highly nutritious vegetables with high energy, dietary fiber, phytochemicals, vitamins, and minerals which offer great benefit for utilization as functional food ingredient. The dried potato powder can be used in formulation of many foods like soups, snacks, sauces, noodles, etc. The foam mat drying involves the dehydration of a thin layer of foam followed by its disintegration in order to obtain a powder which can be easily reconstituted in water when added to other foods. Because of the porous structure of the foamed materials, mass transfer is enhanced leading to shorter drying times and consequently acquiring higher quality in the dried product. Food foams can be considered as biphasic systems where a gas (dispersed phase) is embedded in a continuous liquid phase. The foam properties such as structure, density and stability have important influence on moisture migration during drying and accordingly, the quality of final product. Foams that do not collapse for at least 1h are mechanically or thermally stable for the entire drying process. Response surface methodology (RSM) is a combination of mathematical and statistical techniques which used to investigate the interaction effects of independent variables on responses. There is considerable information on foam-mat dried food powders, but there is not any scientific literature that related to study on foam-mat drying of potato puree. The present research was thus focused on optimizing the foaming conditions (potato puree: gum solution ratio; Arabic gum (AG) concentration as the stabilizer and whipping time [WT]) to minimize foam density (FD) and drainage volume (DV) using RSM. Likewise, choosing a suitable model for thin-layer drying of foam and the effect of different drying temperatures (45, 60 and 80°C) on drying behavior were investigated, and the effective moisture diffusivity and activation energy were calculated. The effects of drying temperatures on water activity (aw) and water binding capacity (WBC) were also investigated.
Material and methods: Fresh potato was purchased from a local market (Mashhad, Iran). Arabic gum was procured from Sigma Chemical Company (USA). For preparation of potato puree, fresh potatoes were washed and peeled by steel knife and were washed again and additional water was taken absolutely and then crushed by Phillips home crusher (600W) with maximum speed for 3 minutes to get a homogeneous puree. Based on preliminary tests, AG solutions were prepared by dissolving a suitable amount of the selected gum powder in distilled water and stirring with a magnetic stirrer to obtain a uniform solution. This solution was refrigerated at 4°C overnight to complete hydration. RSM was used to estimate the main effects of the process variables on FD and DV in potato puree foam. The experiment was established based on a face-centered central composite design (FCCD). The experimental range was chosen on the basis of the results of preliminary tests. The independent variables were consisted of potato puree: gum solution ratio (1:1 –2:1 w/w), AG concentration (0.1–0.9% w/w) and WT (3–9 min). According to the experimental design, to prepare 100 g of samples, appropriate amount of potato puree and AG solution were mixed in a 250-mL beaker. The mixture was then whipped with a kitchen mixer (model no. SM88, Sonny, China) at a maximum speed of 1,500 rpm at ambient temperature during given time which was recommended by Design-Expert software. The density of foamed potato puree was determined in terms of mass over volume and expressed in g/cm3. In order to assess foam stability, the drainage test was performed for 1h. To evaluate drying behavior of the optimized foam, drying was carried out in a batch-type thin-layer dryer at temperatures of 45, 60 and 80°C on 3 mm thickness. Ten thin-layer drying models were evaluated in the kinetics research. The higher value of R2 and lower values of χ2, RMSE and SSE were selected as the basis for goodness of fit. Fick’s diffusion equation for particles with a slab geometry was used for calculation of effective moisture diffusivity. The foamed potato puree spread on a tray was considered as slab geometry. Activation energy was calculated by a simple Arrhenius-type relationship, by plotting the ln (Deff) against the reciprocal of absolute temperature (1/T). Furthermore, the effects of drying temperatures on aw and WBC of powders were investigated.
Results and discussions: The quadratic model was selected as a suitable statistic model for both FD and DV. ANOVA showed that this model is significant for both responses. Moreover, lack-of-fit was not significant for response surface models at 95% confidence level, indicating this model is adequately accurate for predicting responses. The optimum values of variables for best product quality in terms of minimum FD and DV corresponded to potato puree to gum solution ratio 2:1(w/w), AG 0.77% (w/w) and WT 6.80 min. The amount of FD and DV for foam at these optimum conditions were 0.30 g/cm3 and 5 ml, respectively.
The result showed that when the drying temperature increased, the drying time decreased. This was due to the quick removal of moisture at higher temperature. Drying rate (DR) versus moisture content of potato puree foam-mats figure showed that DR was higher during the initial stage as compared with the final stage and foam-mat drying was occurred principally in the constant rate period. Due to the increase in surface area and the porous structure, removal of water from the inner surface of potato puree foam to the outer surface was fast enough to preserve the surface moisture. The rate of movement of moisture from the inner surface to the exposed surface decreased with decreasing moisture content, which indicates that the DR decreased and the falling rate period started. The effective moisture diffusivity varied from 3.286×10-9 to 8.032×10-9 m2/s with activation energy value of 30.97 kJ/mol. Statistical analysis results showed that the Weibull distribution model provide the highest R2 and lowest values of χ2, RMSE and SSE at all drying temperatures. The temperature elevation reduced aw. This is due to the fact that at higher temperatures, the rate of heat transfer to the sample would increase, therefore, it provides greater driving force for moisture evaporation which results the dried foams with reduced aw. Drying temperatures did not show any significant effect on WBC of powders.
Fatemeh Pourhaji; Farideh Tabatabaei Yazdi; Seyed Ali Mortazavi; Mohebbat Mohebbi; Mostafa Mazaheri Tehrani
Abstract
Introduction: Banana is one of the most consumed fruit in the world and is cultivated almost in all tropical countries. This fruit has a high nutritional value and is a suitable source of energy due to the presence of high amount of starch, sugar, vitamin A and C, potassium, sodium, and magnesium. Banana ...
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Introduction: Banana is one of the most consumed fruit in the world and is cultivated almost in all tropical countries. This fruit has a high nutritional value and is a suitable source of energy due to the presence of high amount of starch, sugar, vitamin A and C, potassium, sodium, and magnesium. Banana is highly vulnerable after harvesting and is subject to the microbial spoilage due to the high moisture content which makes difficult its sales and exports. Therefore, several methods have been used to overcome these problems. Drying and dehydration are methods to extend the shelf life of banana which usually carries out by hot air. This method can prevent some degree of microbial spoilage, but it has some disadvantages such as changing color, taste, flavor and reducing the nutritional value.
Foam-mat drying as a substitute for hot air drying introduces some advantages such as using the microwave energy. In this method, food products are whipped to form stable form and then dehydrated by thermal means. Due to the larger surface area and accelerated moisture transfer from foam, food products can be dried at lower temperature and time by this method of drying. Moreover, the porous structure of dried foam results in a faster rehydration and solubility of dried food samples. Additionally, microwave-assisted drying results in a product with better quality because of faster rate and saving energy.
Materials and methods: The fresh banana was cut into small pieces with a diameter of 1.0 mm after peeling. To prevent the enzymatic browning of samples, blanching was carried out by boiling water (100 °C) for 3 min. After that, the banana cuts were placed in a container containing 10°C water in order to cool. To produce pulps, the homemade Bosch mixer (model w600, CNSM, 30EW, Slovenia) at a speed of 1500 rpm and 1.0 min was used. Then, the pulps were mixed with skim milk at different concentrations (3-6 % w/w) and homogenized by ultra-turrax (IKA® Labortechnik) at 10000 rpm for 5.0 min. Moreover; the prepared xanthan gum was added to the mixture at concentrations of 0.15 and 0.25%. Xanthan gum was prepared by adding 1.0 g gum into 100 mL water and mixing by magnet stirrer. Afterwards, the gum solution was kept overnight at 4 °C for complete hydration. Finally, the sample transferred into the foam-maker device which was connected to a nitrogen gas tank with different flow rate (0.2-2 L min-1). The speed and time were adjusted to 16000 rpm and 5.0 min, respectively. After the producing of banana milk foam and selecting optimum sample based on the lowest density and the highest stability, the drying kinetic of this sample was studied. Then the banana milk foam was dried using microwave (360, 660 and 900 V) in a glass plate with diameter of 3.0 and 5.0 mm. Foam density and stability were determined by the methods of Xian-Zheetal (2010), Stauffer (1999) and Bag et al. (2010). The color of samples was studied by hunterlab. Moisture content also was measured based on the AACC standard method (AACC, 2000). Glass transition temperature also was determined by differential scanning calorimetry (DSC, model OIT-500 Sanaf Electronics Co, Iran).
Results and Discussion: In the present study, foam-mat method and microwave drying were used to reduce the drying damages. Nitrogen gas and xanthan gum also were used respectively to control foam generation and improve the stability of foams. Optimization of the banana milk production was carried out using response surface methodology based on three variables including the rate of nitrogen gas (0.2-2 L min-1), concentration of xanthan gum (0.15-0.25 %) and milk to banana ratio (1:6 and 1:3). Optimization was done based on the highest stability and lowest foam density. The optimum condition was proposed as the nitrogen gas rate of 0.2 L min-1, xanthan gum of 0.22 % and 3% banana which showed the density of 0.39 and the highest stability (0 mL after 1.0 h). After that, the optimum sample was dried by microwave. The effects of three levels of microwave voltage (360, 660 and 900 V) and two diameters (3 and 5 mm) were evaluated for drying of optimum sample. The results showed that the sample dried with diameter of 3 mm and voltage of 900 V had the highest L*, highest glass transition temperature and the lowest moisture content.
Adel Dezyani; Aman Mohammad Ziaiifar; Seyed Mahdi Jafari; Mohammad Ghorbani; Alireza Sadeghi Mahoonak
Abstract
Introduction: High sensitivity of fruit and vegetables juices to heat has been resulted to the development of spray drying method for drying this category of products. Spray drying is a well-established and widely used method for transforming a wide range of liquid food products into powder form. The ...
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Introduction: High sensitivity of fruit and vegetables juices to heat has been resulted to the development of spray drying method for drying this category of products. Spray drying is a well-established and widely used method for transforming a wide range of liquid food products into powder form. The process involves spraying finely atomized solutions into a chamber where hot dry air rapidly evaporates the solution leaving the spray-dried particles. Spray-dried powders can be stored at room temperature for prolonged periods without compromising the powder's stability. Powders are cheaper to transport and easier to handle in manufacturing plants. Spray-dried powders are economical to produce compared to other processes, such as freeze-drying. Spray drying has many applications, particularly in the food, pharmaceutical and agrochemical industries. The conversion of high value food materials, such as fruit and vegetable extracts, into particulate form is not easy due to the presence of a high proportion of low molecular weight sugars in their composition which lead to the problem of stickiness. The particles stick to one another, to the dryer and to cyclone walls and remain there, forming thick wall deposits, while very little product comes out at the dryer's exit. This might lead to low product yield and operating problems. In general, the stickiness causes considerable economic loss and limits the application of spray drying on foods as well as on pharmaceutical materials. In order to reduce stickiness, different solutes have been used as carriers and coating agents for the spray drying. Some examples of these are Arabic gum, maltodextrins, starches, gelatin, methyl cellulose, gum tragacanth, alginates, pectin, silicon dioxide, tricalcium phosphate, glycerol monostearate and mixtures of some of them. Of these additives, maltodextrin offers a good compromise between cost and effectiveness. It has been found that it contributes to the retention of some food properties, such as nutrients, color and flavor, during spray drying and storage. On the other hand, the feed flow rate, the inlet and outlet air temperatures, atomizer speed, feed concentration, feed temperature and inlet air flow rate are important factors that have to be controlled in a spray drying process. Tomato paste is a typical example of a product that is very difficult to be spray dried due to the low glass transition temperature of the low molecular weight sugars present.
Materials and methods: This study was carried out to evaluate the effect of inlet air temperature of dryer (120, 150 and 180 °C) and concentration of drying aid or carrier agent of maltodexterin along with whey protein concenterate ratio of 4 to 1 (25, 37.5 and 50% w/w) on the quantitative and qualitative properties of tomato paste powder including moisture content, bulk density, solubility, powder morphology, amount of lycopene, and production efficiency. Response surface methodology was used to choose optimum conditions of the powder production process.
Results and Discussion:the results revealed that the production efficiency (not significant) and solubility (significant) were increased with increased higher inlet air temperatures of dryer; however, at these conditions moisture content (significant), bulk density (not significant) and amount of lycopene (significant) in the powder were decreased also higher concentrations of carrier agent increased the production efficiency, solubility and amount of lycopene in the powder; however, moisture content and bulk density of powder were decreased.
Conclusion: Optimal conditions in order to achieve maximum production efficiency, solubility, the amount of lycopene and the lowest moisture content of powder, bulk density were achieved at inlet temperature of 150°C and carrier agent concentration of (w/w) 50%.
Keivan Ali Asgari; Sakineh Yeganeh; Seyed Ali Jafarpour; Reza Safari
Abstract
Introduction: Nowadays, use of new processing method is important for converting by-products into more marketable and acceptable forms to achieve a better utilization. Sea food processing generate protein rich by-products that their quantity depends on processing method. One of the methods for effective ...
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Introduction: Nowadays, use of new processing method is important for converting by-products into more marketable and acceptable forms to achieve a better utilization. Sea food processing generate protein rich by-products that their quantity depends on processing method. One of the methods for effective protein recovery from this protein rich by-product is preparation of protein hydrolysate through enzymatic, autolytic and chemical hydrolysis. Enzymatic hydrolysis is widely employed to improve the functional and nutritional properties of the fish byproducts. Hydrolysis may be conducted as a method of separating soluble nitrogenous compounds from insoluble particles and fish oil, and offers good predictability of the products. So nitrogen recovery assay can determine enzyme efficiency in separation of soluble protein from insoluble protein. Different factors (Enzyme level, temperature, pH, enzyme to substrate ratio) can effect on the hydrolysis degree, nitrogen recovery and functional properties of protein hydrolysate, so optimization method is used for obtaining the best condition. RSM is a statistical model frequently used for the optimization of complex systems and uses quantitative data from an appropriate experimental design to determine and simultaneously solve multivariate problems. Based on the experimental data, RSM could tell us the optimum conditions to obtain the desired responses, as well as the mathematical model in explaining the relationship between the experimental variables and its responses. Alcalase has great ability to solubilize fish protein and is nonspecific, with an optimum temperature that ranged from 50 to 70°C. It has optimal pH range at the value of 8 to 10 that could reduce the risk of microbial contaminations. Moreover, it has been reported that produced protein hydrolysate by Alcalase had less bitter principles compared to those prepared with papain. Furthermore Alcalase has been documented to be a better candidate for hydrolyzing fish proteins based on enzyme cost per activity.
The Cuttlefish (Sepia offıcinalis) can be found in the south water of Iran including Persian Gulf and Oman Sea and their catch has been recorded about 5102 t according to FAO Statistic. This species has been considered for exporting to other country. During Cuttlefish processing, 30-35 % byproducts including head, arms and viscera are generated that can be invaluable products and environmental pollution while it is protein rich source. The objective of this study was to optimize nitrogen recovery in the enzymatic hydrolysis of head and arms of cuttlefish (Sepia pharaonis) using Alcalase.
Materials and methods: Response surface methodology (RSM) based on Box-Behnken was employed to investigate the effects of different operating conditions including temperature (45, 50 and 55˚C), pH (7.5, 8 and 8.5) and alcalase enzyme to substrate ratio (1, 1.5 and 2) on the nitrogen recovery as a surface response. Referring to the R2 of 0.96 for nitrogen recovery, the mathematical model showed acceptable fitness with the experimental data, which indicated that major part of the variability within the range of values studied could be explained by the model.After obtaining optimum condition for nitrogen recovery, freeze dried protein powder was produced by optimized condition and analyzed for amino acid composition, chemical score of cuttlefish protein hydrolysate and protein efficiency ratio.
Results & Discussion: The obtained results showed the interactive effect of temperature and enzyme to substrate ratio was not significant (P> 0.05) but the interaction effect of enzyme to substrate ratio and pH and the interaction effect of temperature and pH was significant (P
Vahid Mosayebi; Farideh Tabatabaei Yazdi; Zahra Emam-Djomeh
Abstract
Introduction: Pectin is a complex heteropolysaccharide presented naturally in the middle lamella and primary cell walls of plant tissues. Pectin is mostly composed of a linear backbone of α-(1, 4) linked D-galacturonic acid residues which are partially esterified with methyl alcohol or acetic acid at ...
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Introduction: Pectin is a complex heteropolysaccharide presented naturally in the middle lamella and primary cell walls of plant tissues. Pectin is mostly composed of a linear backbone of α-(1, 4) linked D-galacturonic acid residues which are partially esterified with methyl alcohol or acetic acid at the carboxylic acid. Pectin is widely used as a gelling agent in food systems such as jams and jellies, fruit juices, confectionaries, bakery fillings and as a stabilizer in acidified milk drinks. Black mulberry (Morus nigra.L), originating from Iran, is a juicy fruit with dark red color and slightly acidic flavor. Black mulberry has gained an important position in fruit markets and food industry due to its distinctive flavor and phytonutrients in recent years. Black mulberries can be consumed as fresh or processed into several products such as juice, marmalades, liquors, natural dyes or even be used as frozen fruit in ice cream production. However, due to short harvesting season and susceptibility to spoilage, black mulberries are mostly processed into juice besides its fresh consumption. Press cake residue or pomace is the main by-product which is generated in large amounts from the commercial juice extraction processes from berry fruits which contain several bioactive compounds and valuable ingredients including antioxidants, phenolics, pigments, pectin and so on. These berry pomaces are considered suitable for pectin recovery although their pectin content is somewhat lower in comparison to rich known sources of pectin. Recently, ultrasound assisted extraction technique, as a novel method of extraction, has gained remarkable attention due to its some advantageous effects including shorter extraction time, reduced solvent and energy consumption and higher yield and better quality of extracted compounds as compared to conventional acid extraction method. Therefore, the present work was aimed to evaluate and optimize the ultrasound assisted extraction parameters (time of extraction, ultrasound power and liquid/solid ratio) to maximize the extraction yield, degree of esterification and galacuronic acid content of pectin from black mulberry pomace using three level three factor face centered central composite design.
Materials and methods: Fresh and fully ripe black mulberry fruits were purchased from a local fruit market in Karaj (Iran) and subsequently pressed to separate pomace from juice. The obtained pomace was then vaccuum dried (until 7.8±1% moisture content), ground to obtain a homogenous powder, sieved, filled into polyethylene containers, and stored at refrigerator. Pectin extraction from this powdered pomace was carried out using an ultrasonic bath at operating frequency of 35 kHz under different parameters including extraction time (20-60 min), ultrasonic intensity (40-100%) and liquid-solid ratio (15:1 to 30:1 mL/g). The initial pH value of the solution was adjusted to 2.0 by adding 1.0 N HCl solution. At the end of extraction, extracts were quickly cooled, centrifuged, filtered using Buchner funnel, concentrated by 5 fold, coagulated with 96% ethanol (ER=1.5) and left for 8 hours in room temperature. The precipitated pectin was separated by Buchner funnel, rinsed twice with 96% ethanol, dried under vacuum (45°C) and finally powdered. The degree of esterification of pectin was determined by titrimetric method according to Bochek et al. (2001). The galacturonic acid content was quantified by the colorimetric method with m-hydroxydiphenyl reagent using a spectrophotometer at 520 nm. The intrinsic viscosity [ƞ] of pectin was determined using a capillary tube viscometer and accordingly the viscosity average molecular weight [Mv] was calculated from the Anger-Berth equation. Finally, the frequency sweep test was performed using a controlled stress rheometer to determine the values of storage modulus (G′) and loss modulus (G″). The experimental design and statistical analysis were performed using response surface methodology (RSM).
Results and discussion: According to the obtained results, the extraction yield, degree of esterification and galacturonic acid content of pectin varied in the range of 4.73-7.68%, 42.42-58.33 and 18.70-31.45%, respectively. The extraction yield of pectin was linearly affected by the extraction conditions and its value significantly increased with increasing all the studied independent variables (p
Hamid Bakhshabadi; Mohammad Rostami; Masoumeh Moghimi; Abolfazl Bojmehrani; Anehbibi Bahelkeh; Negar Toorani
Abstract
Introduction: Using oilseeds in the human food stuffs, employing their meal for animal feed and also their usage in pharmaceuticals, soap making and fuel has prompted great interest for farmers to plant them and for the government to promote their cultivation. Among them, sunflower is one of the main ...
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Introduction: Using oilseeds in the human food stuffs, employing their meal for animal feed and also their usage in pharmaceuticals, soap making and fuel has prompted great interest for farmers to plant them and for the government to promote their cultivation. Among them, sunflower is one of the main oilseeds in the world which its cultivated area has expanded due to fair cultivation requirements, high yield of the oil, high nutritional value and also lack of anti nutritional factors. Sunflower (Helianthus annuus) is an annual plant belonging to Asteraceae family. This is a dicotyledonous, cross-pollinated monoecious plant that is fertilized by wind and insects. Sunflower seed oil has an excellent nutritional quality, as in recent years, cultivars with high oil (especially oleic acid) content have been substantially nurtured. The most different methods of extracting oil from oilseeds are the press and solvent methods. Similar to the other seeds with high oil content such as canola, the most effective way of extracting oil from sunflower is mechanical pressing followed by solvent extracting. In this method, the mechanical press extracts about 60 percent of the oil and the solvent method extracts the remaining oil. For the first time, the present study was aimed to improve temperature of cooker and moisture of output seeds for producing sunflower oil with lowest degree of insoluble fine partial in oil, moisture and acidity and meal with lowest levels of moisture and oil. Materials and Methods: Sunflower seeds used in this research were supplied from one of Iran's provinces and were transferred to the company of Khorasan cotton and oilseeds to produce oil and meal. After receiving the sunflower seeds in the factory, they were entered into silos in dark and ambient temperature; impurities such as dust, sands, stones, spoiled seeds, small weed seeds and other extraneous materials were separated by mechanical sieves. After cleaning, the seeds were entered into the cracker and they were broken into smaller particles and then were moved into the cooker; at this stage, the temperature of cooker and moisture content of the exiting seeds were set to 70, 80 and 900 C, and 7, 7.5 and 8%, respectively. Then, conditioned seeds were entered into the Buhler flicker device for flaking. Afterwards, the flakes were moved into the Desmet extractor (heating condition of 500C for 7 hours) to extract the oil from the seeds by hexane solvent. Then, the tests were performed on the oil and meal. Severalphysic-chemical properties of sunflower oil including insoluble fine partial, acidity values as well as moisture, protein and oil contents of the obtained meals were determined. Statistical analysis and process optimization were carried out using response surface methodology (RSM). Results and discussion: The achieved results expressed that with an increase in cooking temperature, insoluble fine partial and oil acidity values of the extracted oil were boosted while moisture content of oil and meal values alongside oil content of the obtained meal showed reduction. With increasing of the moisture content of cooker’s seeds, the insoluble fine partial value of the extracted oil was reduced while oil acidity value was increased. Increasing the moisture of cooker’sseeds led to the oil reduction in the meal. The highest oil content in the meal was achieved in the condition that the cooker temperature was 70oC and the moisture of output seeds from the cooker was 7%. The analysis of resulted data showed that two parameters of the cooker’s temperature and cooker’s seeds moisture content had significant effects on the moisture content of the meal. Increasing the cooker temperature from 70 to 90oC caused a decrease in the meal moisture. As result shown, increasing the moisture content of output seeds from the cooker increased the moisture content of the meal. Increasing the cooker temperature from 70 to 90oC reduced the protein amount of the meals. Results of different studies showed that increasing the temperature will decrease the protein amount of the meals. Increasing the moisture was also resulted in the decrease of residual protein in the meal. The obtained results of the optimization procedure revealed that the application of the cooking temperature of 70 °C and moisture content of the output seeds equal 7.73 and 7.65 % led to achieving products with the least values of acidity and insoluble fine partial in the obtained oil as well as meals with the minimum remaining oil.
Adieh Anvar; Behzad Nasehi; Mohammad Noshad; Hassan Barzegar
Abstract
In this study, microwave drying conditions of quince pomace optimized with respect to quality attributes (moisture content, color change and consumer acceptance). Response surface methodology (RSM) technique was used to develop models to respond to the microwave power (100, 2000, 300 W), and microwave ...
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In this study, microwave drying conditions of quince pomace optimized with respect to quality attributes (moisture content, color change and consumer acceptance). Response surface methodology (RSM) technique was used to develop models to respond to the microwave power (100, 2000, 300 W), and microwave time (5, 10, 15 min). The models obtained from the responses were adequate and acceptable because the coefficient of determination R2 of the models was relatively high. Microwave power of 200W and microwave time of 8 minutes were concluded as the optimum conditions prior to air-drying at 50°C. To describe the drying process, the experimental data for moisture loss was converted to moisture ratios. The effective moisture diffusivity increased with increase in microwave power and its values varied from 1.83-4.87×10-9 m2/s. Using an exponential expression based on Arrhenius equation the activation energy and was found to be 16.41 W/mm.
Behrooz Alizadeh Behbahani; Ali Alghooneh; Farideh Tabatabaei Yazdi; Fakhri Shahidi; Mohebbat Mohebbi
Abstract
Introduction: Avicennia marina, commonly known as gray or white mangrove, is a specie of mangrove tree classified in the plant family Acanthaceae. It is distributed along Africa's east coast, south-west, south and south-east Asia, and southern Iran along the Persian Gulf coast. It grows as a shrub or ...
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Introduction: Avicennia marina, commonly known as gray or white mangrove, is a specie of mangrove tree classified in the plant family Acanthaceae. It is distributed along Africa's east coast, south-west, south and south-east Asia, and southern Iran along the Persian Gulf coast. It grows as a shrub or tree to a height of three to ten meters. Mixture design is one of the most popular smart systems which is based on simulation of linear and non-linear systems using mathematical and statistical techniques, and a useful tool for dealing with completely unknown systems. Chemical preservatives are commonly used for inhibition of pathogens in foods, people are concerned about the side effects of preservatives on their health. Replacement of chemical preservatives with natural substances have a great importance in food preservation. Natural preservatives, as well as, essential oils and plant extracts are suitable alternatives for chemical preservatives. The main purposes of this study are the evaluation of the effects of different combinations of four solvents (water, ethanol, methanol and glycerin) on the efficiency of mangrove leaf extraction using response surface method with mixture optimal design, the optimization of solvent formulation for mangrove leaf extraction, and, finally, the evaluation of the in vitro inhibitory and bactericidal effects of mangrove leaf extract on Listeria innocua ATTC33090 ، Enterococcus faecium ATTC 51559 and Escherichia coli ATTC 25992.Materials and method:Fresh mangrove leaves were prepared from Qeshm Island, Persian Gulf, Iran, in August 2012. Water, ethanol, methanol and glycerin extracts were prepared by adding 50 g of powdered mangrove leaf to 250 mL of the solvent. Extraction was carried out for 48h, in ambient temperature. The mixture of extract and leaf powder was separated by Watman filter paper, then the filtrate was centrifuged in 3000g for 10 minutes and filtered using a 0.45 µm Millipore filter. Finally, in order to separate the solvent and concentrated extract, the solutions were evaporated using a rotary vacuum evaporator. The concentrated extract was stored in dark aluminum containers at 4°C. In this study, the effects of water, ethanol, methanol and glycerin at five levels (0, 31.25, 83.33, 125 and 250 ml) on efficiency of mangrove leaf extraction by mixture optimal design has been investigated. Modeling and optimization has been carried out by Scheffe polynomial. The antimicrobial activity of mangrove leaf extract was evaluated using disk diffusion method. The minimum inhibitory concentration (MIC) of mangrove leaf extract was determined using serial dilution tubes. For each extraction method (based on solvent, Water, Ethanol, Methanol and Glycerin), 8 serial concentrations (2, 4, 8, 16, 32, 64, 128, 256 mg/mL) and 1 control tube of mangrove leaf extract were prepared in Mueller-Hinton broth. The minimum bactericidal concentration (MBC) of mangrove leaf extract was determined using serial dilution tubes.Results and Discussion:The Results indicated that Scheffe polynomial model was highly significant for prediction of efficiency of mangrove leaf extraction (R2 and R2adj values equal to 0.940 and 0.8447, respectively and The lack-of-fit tests did not result in a significant, also F-value (14.62) indicated that the model is sufficiently accurate). The optimum formulation was found as following: glycerin (0 ml), water (28.22 ml), methanol (59.83ml) and ethanol (161.95 ml) respectively. Maximum of antimicrobial effect on Listeria innocua and highest resistance against mangrove leaf extract on Escherichia coli were observed. Increasing concentration of mangrove extracts had a significant effect (p< .05) on inhibition zone diameter. This may have been resulted from the increment of the solvent polarity associated with glycerin increase. In order to study the mentioned hypothesis, Pearson Square statistical test was used to determine the correlation between the extraction rate and polarity. The results showed that a significant (P≤0.05) and inverse relationship between the extraction rate and polarity of the solvent. Moreover, in order to check the accuracy of the model fitted on the data obtained from mangrove leaf extraction rate the goodness of fit was investigated using both coefficient of determination (R2) and lack of fit test. A 94% coefficient of determination and lack of significance (P≤0.05) for lack of fit test suggested that Schef model could accurately fitt the data and predict it The results of this study showed that Schef polynomial and numerical optimization using mixture design method were suitable to fit efficiency of mangrove leaf extraction and solvent formulation optimization data, respectively. According to the results, the optimized solvent formulation was glycerin (0 mL), water (28.22 mL) and ethanol (161.95 mL). Conclusion: Finally, the results showed that mangrove leaf extract had a notable antimicrobial effect on the studied strains “in vitro”. More “in vivo” studies seem to be required in order to determine the best extract dosage which leads to inhibition of microbial infection.
