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 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
Narjes Babaei; Mohammad Goli
Abstract
Introduction: Diabetes recognized as one of the most important health problems and the most common metabolic disease in the world. The prevalence of diabetes is increasing worldwide, including in Iran (Forouhi & Wareham, 2010). Celiac is a disease in which the mucous membrane of the small intestine ...
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Introduction: Diabetes recognized as one of the most important health problems and the most common metabolic disease in the world. The prevalence of diabetes is increasing worldwide, including in Iran (Forouhi & Wareham, 2010). Celiac is a disease in which the mucous membrane of the small intestine of a person with wheat gluten intolerance damaged by gluten and causes intestinal inflammation (Hopper et al., 2007). Stevia rebaudiana bertoni belongs to the Astrasse family, a perennial natural, calorie-free sweetener that has a sweetening power of 100 to 400 times greater than sucrose (Agarwal et al., 2009). Isomalt, a polyol, used as sugars substitute (sucrose, high fructose corn syrup, glucose syrup, etc.) (Schiweck and Munir, 1992). This study aimed at producing dietary Sohan-Pilaki for diabetic and celiac patients using replacement of sucrose with Stevia-Isomalt and the complete replacement of wheat flour with rice-corn flour. Rice and corn flour used to improve the textural and nutritional properties. Material and Methods: For production of dietary Sohan-Polaki, the raw materials (white sugar 40.03%, sorbitol liquid 16.01%, vegetable oil 32.03%) transferred to the kettle for melting over a gentle flame followed by adding the rest materials such as rice and corn flour (8.1%), egg yolk (3.2%) and cardamom (0.72%). The final dough then poured into the tray container after splicing and finishing the production operation and after being chilled and formed to the required dimensions by the forming machine. For the preparation of dietary Sohan-Polaki, independent variables were included, replacement of Stevia-Isomalt with surface (0 to 100%), rice to corn flour ratio (0 to 100%) and cooking temperature (160 to 180°C). All other compounds considered constant. Isomalt is a substitute for sugar as a filler. To obtain optimal points, 34 experiments proposed by Design Expert software, central composite design response surface methodology, double in the other points, six central points with alpha 2. Test responses included density (replacement of rapeseed, Naghipour et al., 2013), textural properties, i.e., hardness (TPA, Khazaiy Pool et al., 2015), color changes assessment (Lab, Image J, Aslanzadeh et al., 2014). Results and Discussion: Isomalt causes increasing the rigidity and led to a decrease in porosity and ultimately a decrease in density (Bagherpoor and Khosroshahi Asl, 2016). The quality of the sweets eaten directly related to their texture characteristics. Among the various textural parameters, hardness considered to be an important characteristic, which refers to the maximum force curve height at the first pressure and represents the maximum force applied during the biting operation (Cheng and Bhat, 2016). The amount of moisture, dry matter, amount and type of protein and fat also have some effect on hardness. In addition, at high levels of replacement wheat with corn flour, hardness increased with increasing Stevia-Isomalt content. Increasing the sucrose concentration due to its effect on the corn starch chains of the amorphous region, causes granulation of the starch and stabilization of the gel, leading to harder gel formation (Sun et al., 2014).Discoloration caused by caramelization and non-enzymatic browning reactions due to rising temperatures. As the temperature increases, the oxidation of the fats becomes more intense, which in turn has a significant effect on the color of the dyes studied (Ghandehari Yazdi et al., 2018). Since non-sucrose sweeteners play an important role in lightness changes, they are also associated with caramelization and the Millard reaction (non-enzymatic browning) between reducing sugars and amino acids. Sucrose (non-reducing sugar) at high temperatures converted to glucose and fructose (reducing sugars). Thus, if the amount of sucrose reduced, the color intensification is weaker due to the lower formation of the products from the reaction of Millard (Gonzalez-Mateo et al., 2009).Overall, according to the type of flour consumed in the Sohan-Polaki formulation, the two final optimal formulas, i.e., optimal formula 1, including sucrose replacement with Stevia-Isomalt 24%, the ratio of rice to corn flour 0.99 and cooking temperature of 166°C ( With a density of 1.37 g/cm3, the hardness of 1.85 N and color changes compared to the control 3.66) and optimal formula 2, including sucrose replacement with Stevia-Isomalt 24%, the ratio of rice to corn flour 0.02, and cooking temperature of 180°C (with a density of 1.23 g / cm3, the hardness of 2.07 N and color changes compared to the control of 10.16) were introduced as the best treatments.
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%.
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
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.
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.
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
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.
Mahmoud Yolmeh; Mohammad Bagher Habibi Najafi; Reza Farhoosh; Fereshteh Hosseini
Abstract
IntroductionFood consumers tend to use natural products without any synthetic additives. Therefore, many studies have been conducted to investigate the possibility of replacing synthetic additives with natural substances in various food products.Annatto dye is a natural carotenoid pigment extracted from ...
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IntroductionFood consumers tend to use natural products without any synthetic additives. Therefore, many studies have been conducted to investigate the possibility of replacing synthetic additives with natural substances in various food products.Annatto dye is a natural carotenoid pigment extracted from the pericarp of BixaorellanaL. seeds. The major fraction of the annatto extract is 9´-cis-bixin that is soluble in oil and 9´-cis-norbixin is the major dye fraction of the alkaline extract that is soluble in water. Annatto dye creates orange to red color in food and to be used as a natural pigment in a variety of food materials including cheese, butter, margarine, confectionary and bakery products, different kinds of drinks, snacks and jams. In addition, annatto dye has antioxidant and antimicrobial activity.Nowadays, the extraction of natural dye from plant resources has become a common technology. However, complementary information using new methods and optimization of the extraction conditions seems to be necessary in order to accomplish the highest yield of extraction. Response surface method (RSM) is effective and efficient in optimizing color extraction conditions.In this study, the different conditions of extraction process were optimized through RSM in order to obtain maximum yield and best quality of annatto dye.Materials and methodsMaterialsAnnatto seeds were purchased from Hyderabad, India. All solvents were analytical grade, Merck, Germany.Extraction of annatto dyeA certain amount of annatto seeds was soaked in n-hexane for 6 hours in order to remove oils. After filtration, the defatted seeds were used for dye extraction. Since chloroform and acetone showed the highest yields of extraction during preliminary experiments, these two solvents and their mixtures were exploited for the final experiments assigning 0 for pure acetone and 100 for pure chloroform. The extracts were filtered through Whatman filter paper NO.1 and then vacuum-dried in the 1410D-2E vacuum oven (Shel Lab, USA) to produce dye powder. Low temperatures (40°C) were applied to prevent thermal dissociation of conjugated double bonds during drying. Dye measurementThe coloring strength was measured according to Vasu et al. method; model UV-160A spectrophotometer Shimadzu, Japan, at 502 nm in which bixin has the maximum absorbance value when it is dissolved in chloroform.Determination of extraction efficiencyThe obtained powder was weighed and the mass ratio of the powder to the weight of the seeds was taken into account as the extraction yield.Experimental designIn this study, Minitab® software version 16.1.1 (Minitab Inc. USA. 2010), was used and a five level four factor central composition design was created to investigate the effect of the independent variables such as temperature, extraction time, seed to solvent ratio and chloroform concentration on the dependent variables namely the extraction efficiency and absorbance values.Results and DiscussionThe values of R2, R2-adj and R2-pred revealed that the full quadratic models were the most adequate for the extraction efficiency and absorbance values.The all of the linear terms show a significant effect except the extraction time (P< 0.05). The quadric term of extraction time and the seed to solvent ratio also had a significant effect (P< 0.05) on the extraction efficiency, however, the effect of other two quadric terms was insignificant (P> 0.05). The interactive terms of extraction temperature* seed to solvent ratio(X1X3) and the seed to solvent ratio*Chloroform concentration (X3X4) had a significant effect on the extraction efficiency (P< 0.05); however, the other two interactive terms was insignificant (P> 0.05).For the absorbance values, the all of the linear terms show a significant effect (P < 0.05); the quadric term of extraction temperature (X12) and the seed to solvent ratio (X32) also had a significant effect (P< 0.05) on absorbance values, but, the effect of other two quadric terms (X22 and X42) did not show a significant effect (P> 0.05). The all of interactive terms was insignificant (P> 0.05).An increase in the extraction efficiency was observed with the increasing temperature. Banik and Pandey while extracting oleanolic acid from Lantana camararoots demonstrated that as temperature increases extraction efficiency improves too. However, at temperatures higher than 70 °C, the annatto seed pigments were degraded and the response was reduced so the quadratic effect of temperature was negative. The absorbance value was increased by increasing the temperature; however, the absorbance value decreased at higher temperature by thermal decomposition and damage of the conjugate double bond.The absorbance value increased by increasing the chloroform concentration and seed to solvent ratio initially, however, subsequently decreased due to the damage of the conjugate double bond in higher chloroform concentration and saturation of solvent in higher seed to solvent ratio.Temperature of 48.33 ˚C, extraction time of 2 hr, the ratio of seed to the solvent of 12.88 and chloroform concentration of 100% were found to be as the optimum conditions of the process. The extraction efficiency of 3.95 percent of annatto seed and absorbance value of 0.597 were acquired as the predicted results.
Zahra Ahmadian; Mehdi Varidi; Mohammad Javad Varidi; Hashem Pourazerang
Abstract
High nutritional value and existence of bioactive components in sesame seeds converted it to a valuable food. One of the methods to increase per capita consumption is processing of sesame with different ways such as production of sesame milk. In this study, the effect of blanching time (0 as a control ...
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High nutritional value and existence of bioactive components in sesame seeds converted it to a valuable food. One of the methods to increase per capita consumption is processing of sesame with different ways such as production of sesame milk. In this study, the effect of blanching time (0 as a control sample, 15 and 30 min) at 95°C and roasting temperature (0 as a control sample and 145°C) for 20 minutes was evaluated on the physicochemical and sensory characteristics of sesame milk using completely randomized factorial design. Blanching of sesame before the milling, resulted in significant decrease of the fat content, viscosity and physical stability of sesame milk .Also, roasting of sesame seeds significantly reduced the total solid content, fat and physical stability of sesame milk, while the amount of ash and specific gravity significantly increased. The results of color analysis showed a significant increase in brightness (L *) of sesame milk from 83.864 in control sample to 88.941 with increase of blanching time to 30 minutes. Moreover the total color differences showed a significant decrease from 15.371 in control sample to 10.435 with increase of blanching time to 30 minutes. Finally, by optimization of processing, the best physicochemical and sensory properties of sesame milk achieved with blanching for 15 minutes at 95°C and roasting at 145°C for 20 minute.
Masoud Hashemi Shahraki; Aman Mohammad Ziaiifar; Mahdi Kashani-Nejad; Mohammad Ghorbani
Abstract
Oil uptake occurs mainly during cooling immediately after frying. Post-frying centrifuge step used to remove the attached oil to the surface of friedproduct. Response surface methodology (RSM) technique was used to develop models for the responses to the centrifugal force (100, 200 and 300 rpm) and centrifugal ...
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Oil uptake occurs mainly during cooling immediately after frying. Post-frying centrifuge step used to remove the attached oil to the surface of friedproduct. Response surface methodology (RSM) technique was used to develop models for the responses to the centrifugal force (100, 200 and 300 rpm) and centrifugal time (20, 50 and 80 s), frying temperature (140, 170 and 200 C) and frying time (4, 6 and 8 min), Investigated factorsoptimized with respect totheoil and moisture contents, color and textural parameters. The models showed very well fitness with experimental data. The coefficients of obtained models with RSM, was optimized by using genetical gorithms and was observedthat GA optimized models showingbetterfitnesswith theexperimentalresults than RSM models. The resultssuggest thatpost-frying centrifuge step in300 rpm for 80 sand fryingin 175-180Cfor 7-8 minleadsto French fries withlowestmoisture and oil contentand best color and texture.
Nafiseh Vahedi; Mostafa Mazaheri Tehrani; Seyed Mohammad Ali Razavi; Rassoul Kadkhodaee
Abstract
Low-fat butter is water in oil emulsion comprising a continuous fat phase including butter, emulsifiers and colorants and also a dispersed aqueous phase including water, stabilizers and proteins. In this research, by using protein components especially full-fat soy flour, a product were produced which ...
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Low-fat butter is water in oil emulsion comprising a continuous fat phase including butter, emulsifiers and colorants and also a dispersed aqueous phase including water, stabilizers and proteins. In this research, by using protein components especially full-fat soy flour, a product were produced which has extreme similarity to ordinary butter and also has good organoleptic properties. Water : butter ratio, soy flour : sodium caseinate ratio and emulsifier content were the designed factors and their effects on sensory properties of low-fat butter such as softness, spreadability, crumbling, hardness, adhesiveness, cohesiveness, melting rate, mouth coating, gumminess, butter flavor, soy flavor and finally overall acceptance were evaluated. The Central Composite Design (CCD) and Response Surface Methodology (RSM) were employed as experimental design and statistical analysis. Based on final results, the optimum formulation for low-fat butter were: water : butter ratio as 1.03 (50% water and 48.5% butter), soy flour : sodium caseinate as 1.57 (5% soy flour and 3.2% sodium caseinate) and 0.66% emulsifier. Apart from good nutritional effects of final product due to high protein content and lower fat content, that was spreadable at low temperatures and also has plastic characteristics of butter at ambient condition.
