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.
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.
Sara Karamzadeh; Sara Ansari
Abstract
Introduction: Pectin is a complex mixture of polysaccharides in the primary cell wall of plants which is a polymer of α-galacturonic acid, to which neutral sugar is connected to form aside chain. Pectin is a natural food additive used extensively in the food industry as thickener, texturizer, emulsifier, ...
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Introduction: Pectin is a complex mixture of polysaccharides in the primary cell wall of plants which is a polymer of α-galacturonic acid, to which neutral sugar is connected to form aside chain. Pectin is a natural food additive used extensively in the food industry as thickener, texturizer, emulsifier, stabilizer and gelling agent. In 2018, the world market demand for pectin was in excess of 60,000 tons and Europe was estimated to have the largest market with 31,000 tons (valued about US$420). In Iran, about one hundred tons of pectin is consumed annually in the food and pharmaceutical industries, all of which are supplied from abroad, and due to its price in the world market is of considerable magnitude. Therefore, the study of its production within the country could be of great importance. During processing and canning of eggplant, its cap and skin are discarded as waste which can be considered as a valuable ingredient in the food industry. The main objective of this study was to develop an MAE (Microwave assisted extraction) of pectin from eggplant peel and investigate the effect of process variables (microwave power, irradiation time and pH) and the response (extraction yield, degree of esterification, galacturonic acid content and emulsifying activity); and to obtain optimum conditions for maximum extraction yield of pectin from eggplant peel. The response surface methodology (RSM) using Box-Behnken design was employed in this study. Material and methods: Eggplant peels were provided by Yek-o-Yek factory as an unwanted by-product. Then, the peels were divided into small pieces and dried in hot air oven at 65 °C until it attains constant weight. The peels were then grinded and passed through a 40-mesh sieve to obtain powdered sample. The independent variables examined were microwave power (360–450–540 W), irradiation time (1–2.5–4 min) and solution pH (1–2–3). MAE of pectin was performed in an ordinary household microwave oven with a total of 17 treatments according to RSM. About 5 g of dried eggplant peel powder was weighed and placed into a 250 ml beaker, 75 ml distilled water (the liquid-solid ratio 15:1 v/w) containing different pH values was added and exposed to microwave radiation at different powers for the selected irradiation times. After microwave heating, the mixture in the beaker was allowed to be cooled down and filtered using filter paper (Whatman no-1). The filtered extract was centrifuged and the supernatant was precipitated with an equal volume of 98% (v/v) ethanol. The coagulated pectin mass was washed with 98% (v/v) ethanol for two times and dried in oven at 60 ° C until it attains constant weight. The pectin extraction yield was calculated by dividing the weight of dried pectin to the weight of dried eggplant peel powder. Galactoronic acid content of pectins was determined using the meta-hydroxydiphenyl method. The esterification degree of the pectins was determined by the titrimetric method with minor modifications. The emulsifying activity (EA) of the eggplant peel pectins were analyzed according to the method by Dalev & Simeonova (1995). Optimum extraction conditions to achieve maximum extraction efficiency, degree of esterification, galacturonic acid content and emulsifying activity were determined. Then, the stability of the oil-based emulsion prepared by mixing 0.5% w/w solution of pectin extracted in optimal conditions and corn oil, were examined at 4 and 23 ° C. In addition, the behavior of pectin extracted under optimal conditions (at concentrations of 0.1, 0.2, 1 and 2%) and its spectra using a Fourier transform infrared spectrometer (FTIR) were investigated. Results and discussion: The results indicated that the extraction efficiency, esterification degree, the amount of galacturonic acid, and the emulsifying activity of the pectins extracted were 2.20- 17.16%, 20.20- 36.13%, 51.3- 74.7%, and 1.87- 21.64%, respectively. With increasing microwave power, irradiation time and decrease of solution pH the extraction efficiency of pectin extracted increased, while esterification degree decreased. The amount of galacturonic acid and emulsifying activity showed an upward trend up to microwave power of 450 watts and the irradiation time of 3 minutes after which demonstrated a downward trend. The optimum conditions for reach to the maximum extraction yield, galacturonic acid content and emulsifying activity were in microwave power of 360 W, irradiation time of 4 min and pH of 1 that at these conditions, the extraction yield of 16.17, galacturonic acid content of 70.81 and emulsifying activity of 2.68 were predicted. Also, these observations indicated that with increase in concentration, the flow behavior of pectin solutions was changed from Newtonian to pseudo-plastic. In addition the stability of pectin-stabilized emulsion at 4°C was more than 23°C. In general, this study showed that the microwave method could be used as a novel and high-performance method for extracting pectin from eggplant peel.
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.
Atefe Maqsoudlou; Alireza Sadeghi Mahoonak; Mohammad Ghorbani; Fidel Toldta
Abstract
Introduction: Bee pollen, commonly referred as the ‘‘life-giving dust’’, results from the agglutination of flower pollens with nectar using salivary substances of the honeybees (Almeida-Muradian et al., 2005). Pollen contains 10 to 40% protein, 1 to 13% lipid, 13 to 55% carbohydrates and 2 to ...
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Introduction: Bee pollen, commonly referred as the ‘‘life-giving dust’’, results from the agglutination of flower pollens with nectar using salivary substances of the honeybees (Almeida-Muradian et al., 2005). Pollen contains 10 to 40% protein, 1 to 13% lipid, 13 to 55% carbohydrates and 2 to 6% minerals. Royal Jelly is produced by enzymatic digesting of bee pollen by proteases and other natural enzymes. Based on dry weight, it contains 27-41% protein, 30% carbohydrates, 8-19% lipids, minerals, trace elements and some vitamins (Sabatini et al., 2009; Wytrychowski et al., 2013). The antioxidant properties of royal jelly and bee pollen, are related to main proteins and phenolic compounds and flavonoids (Nagai and Inue, 2004). The antioxidant activity of peptides can be evaluated using DPPH, radicals scavenging activity, Ferric reducing, Ferrous chelating activity (Khantaphant et al., 2011). Antioxidant and ACE inhibitory activity of pollen, royal jelly and peptides were investigated by different researchers (Bogdanov, 2014; Morais et al., 2011; Salampessy et al., 2015; Marinova and Tchorbanov, 2010; Wiriyaphan et al., 2012). The objective of present research was optimization of enzymatic hydrolysis of bee pollen protein by Alcalase according to its antioxidant and ACE inhibitory activity compared to royal jelly.
Materials and methods: The preparation of the bee pollen extract was performed by mixing the bee pollen with water (1:10) (w/v). The macerates were filtered and centrifuged at 12000 g. The obtained supernatant was lyophilized. The royal jelly extract were prepared using method described by Liu et al., 2008. The total phenolic content of the extracts was recorded using the Folin–Ciocalteu method (Moreira et al., 2008). DPPH radical-scavenging activity was determined as described by Bersuder, Hole, and Smith (1998). The ability of the hydrolysate to reduce iron (III) was determined according to the method of Bougatef et al. (2008). Bee pollen was added and homogenized with 5 volumes of distilled water. pH and temperature of the solution were adjusted to pH=8 and 50◦C. Alcalase in the concentration range of 1 to 2% w/w were added to the pollen protein solution. Enzymatic hydrolysis performed during different times 2 to 5 hours. Hydrolysis was stopped by heating at 80˚C for 10 min. The hydrolysats were centrifuged at 4000x g for 30 min to remove the residue. The supernatants were pooled and then lyophilized (Matsuoka et al., 2012). DPPH radical scavenging ability and reducing power of pollen hydrolysates of pollen hydrolysates were measured. Also ACE-inhibitory activity of pollen hydrolysates was measured was assayed by method reported by Nakamura et al. (1995). Statistical analysis of results before hydrolysis was done by SPSS. Optimization of enzymatic hydrolysis was done by Response Surface Methodology (RSM) in Design Expert software.
Results and discussion: Total phenol value measured for pollen ranged between 48.15 to 174 mg Gallic acid/g for royal jelly ranged from 9.24 to 87.261 mg Gallic acid/g. Considering that royal jelly is obtained by direct digestion of pollen, the amounts of their phenolic compounds were comparable (Bogdanov, 2014). Phenolic compounds increased by increasing concentration royal jelly and pollen extract in dose dependent manner. Increasing concentrations of royal jelly in range of 300 to 1000 mg/l was more effective than pollen (p
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%.
Bahareh Davarnia; Ali Motamedzadegan; Gholamhasan Asadi; Abdolmohammad Abedian Kenari; Mahmoudreza Ovissipour
Abstract
Enzymatic hydrolysis of Yellowfin tuna visceral protein with Neutrase has been carried out by response surface methodology using factorial design. Peptide chain length was estimated as the response surface to the hydrolysis conditions (enzyme activity, reaction temperature, and reaction time). The tuna ...
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Enzymatic hydrolysis of Yellowfin tuna visceral protein with Neutrase has been carried out by response surface methodology using factorial design. Peptide chain length was estimated as the response surface to the hydrolysis conditions (enzyme activity, reaction temperature, and reaction time). The tuna visceral protein hydrolysate had relatively high protein (74.56%) and low lipid content (1.86%). R2 of 0.85for the mathematical model indicated that 85% of the variability within the range of values studied could be explained by the model. Enzyme activity of AU/kg protein, temperature of 50°C, and hydrolysis time of min were the optimal conditions of hydrolysis. The electrophoresis pattern of the Yellow tuna hydrolysate showed no peptides size bigger than 10 KDa. The chemical score of the hydrolysate indicated that it fulfils the nutritional requirements of children with age 10-12 except Lysine and Methionine. Lysine and Methionine were the first and the second limiting amino acids, respectively and in case of children with age 2-5 lysine was predominant amino acid in the hydrolysates. It could be concluded that by application of enzymatic hydrolysis of Yellowfin tuna viscera protein, the properties of protein hydrolysate was improved.
