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Some Biochemical properties of silver carp surimi prepared by application of acid-alkali aided methods were investigated and compared to that of derived by conventional method. In terms of total protein solubility and recovery, lipid reduction, and total pigment extractability and myoglobin removal there was a significant (P<0.05) difference among the treatments. Acid-aided method showed the most efficiency to recover more proteins (86.2%) in comparison to the alkaline-aided (79.8%) and conventional (76.7%) methods. The lipid reduction percentage was recorded as 43.6%, 58.4% and 72.3% for the conventional method, and acid-alkali aided methods, respectively. In terms of total pigment removal, the conventional method showed higher efficiency (P<0.05) compared to the pH-shifting methods. Conversely, fish protein solubilisation by acid-alkali aided techniques was more efficient (P<0.05) compared to the conventional method of making surimi. In conclusion, pH-shifting techniques were superior in comparison with the conventional method in order to recover more functional proteins and to efficiently reduce the lipid and myoglobin content of resultant fish protein isolate.

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The present study was conducted to evaluate the efficacy of the pH-shift process in protein recovery from whole and gutted common kilka and characteristics of the produced gel compared with muscle surimi obtained with the conventional method. Although both acidic and alkaline methods reduced total pigment (TP) in isolates obtained from the whole and gutted fish, the alkaline version was more effective and the lowest amount of TP was observed in the isolate from gutted fish using alkaline version. The last sample also contained the lowest amount of TCA soluble peptide which was significantly lower than the others. Also, gel produced from the isolate recovered form gutted kilka with the alkaline version had significantly higher water holding capacity and gel hardness but it was weaker than the sample obtained with conventional method. The results were supported with higher relative amount of actomyosin and actin in the structure of the gels produced from the gutted fish isolate and surimi from fish muscle, as reflected in SDS-PAGE. Nevertheless, the whiteness of the samples recovered with pH-shift process was quite lower than the muscle surimi which reveals the necessity of more research in this area.    

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Lipid oxidation is one of the major processes in deterioration of food quality and nutritional value. In this study, antioxidative activity of peptide was determined from hydrolysate of protein isolate from common kilka (Clupeonella cultriventris caspia) muscle using trypsin enzyme of pyloric caeca extraction. The optimum pH and temperature of trypsin enzyme for BAPNA (Nα –benzoyl -DL- argentine – ρ – nitroanilide -HCL) hydrolysis were measured 8.0 and 60 °C, respectively. The finding showed that antioxidative activities determined by DPPH, ABTS radical scavenging activities and ferric reducing antioxidant power (FRAP) increased significantly with variation of degree of hydrolysates from 20 to 40% (p<0.05). The results suggest that trypsin enzyme from pyloric caeca extraction could be a useful tool for peptide production from protein isolate with antioxidant activity and used as an alternative for commercial enzymes such as microbial enzymes in production of protein hydrolysates.

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  Due to the environmental hazards of using plastic films, studies on the development of plant based films such as soy protein films, are receiving more attention.  In this research, edible films were prepared from soy protein isolate and the effect of glycerol as a plasticizer at three concentration levels of 0.4, 0.6 and 0.8 g/g of soy protein isolate on the properties of these films was investigated. Some Mechanical properties, i.e. tensile strength and extension, and physical properties, i.e. water vapor transmission rate, opacity, water adsorption and solubility were examined. Films prepared without glycerol were very brittle and could not be examined. Results showed that increasing the concentration of glycerol led to a significant (p<0.05) increase in extension rate and decrease in tensile strength of soy protein isolate films. Solubility percentage, water adsorption and water vapor transmission rate of the films were found to increase when the glycerol level increased.  Although glycerol addition reduced the opacity of the films, its concentration did not have a significant correlation with this parameter (p<0.05).

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The objectives of this study were to investigate the potential of faba bean protein isolate (FPI) in preparation of an edible film and to determine the effects of film forming solution pH and plasticizer concentration on film properties. So film samples were prepared in three different pH levels (7, 9 and 12) and plasticizer concentrations (40, 50 & 60% w/w protein isolate). Results showed that increasing of pH improved mechanical properties (tensile strength and elongation) and solubility of films but caused water vapor permeability (WVP) and lightness of films to decrease. Plasticizer concentration did not affect WVP over the studied range. Elongation and solubility of films increased and tensile strength decreased by increasing of plasticizer content of film forming solutions. The lowest WVP and the highest tensile strength was observed at pH 12 and 40% (w/w of FPI ) glycerol concentration.

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  Macaroni and pasta products are one of the favorite dishes in the world. In Iran, it improves its position in family food programs. In recent years, using additives and different components to improve quality and nutritional properties of this product have been used. Soy protein isolate (SPI) added to semolina to improve quality and quantity of protein and amino acid profile of final product such as macaroni. The aim of this study was the effects of adding different level of SPI (1, 2, 4 and 6% on semolina basis) on the properties of macaroni have been investigated. Result showed that by increasing the amount of SPI, water absorption of dough was decreased. Also by increasing the amount of SPI, the value of protein and ash contents were increased. Although the amount of soluble solid, cooking quality index, moisture content and pH value had fluctuation. Sensory evaluation of products in terms of color, taste, chew ability and stickiness were determined by 5 trained panelists. These two samples and control sample were evaluated by 30 untrained panelists with using preference test. The result showed that the sample contained 2% SPI was recognized the best regarding chemical, rhological and cooking quality index. In order to determine amino acid profile, the sample containing 2% SPI and the control sample were analyzed by HPLC. The result indicated that the amounts of amino acids were increased but methionine did not. Lysin and Hysidin showed maximum and minimum increase respectively 32.1% and 2.2%.  

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   Edible coating are thin layers that are on surface of food materials and they are such as protector. Films and edible coating which are prepared from natural polymers specially protein are under consideration in recently years. Aim of this search, is possibility of production of edible film from chickpea protein isolated and determinate the effect of chickpea protein isolated concentration and plasticizer percent on some properties of edible film. So was considered with using from central composite design of chickpea protein isolated in concentrations 4 -10 g, and glycerol plasticizer in range of 40- 60% of weight of chickpea protein isolated in pH=9.5. In this study was considered physical and qualitative examination like water vapor permeability, film solubility, transparency of edible films. Results showed that percent of plasticizer in experiments had right effect on water vapor permeability; thus increasing of protein concentration was caused increasing of water vapor permeability measure at statistical surface (P<0.01). the increase of plasticizer concentration, is caused solving  of films and increase of protein isolated concentration is caused to decrease of transparency of edible films.  

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Chickpea proteins have received attention during recent years owing to their higher biological values and better functional properties than oilseed proteins.  In present study, the effect of protein extraction method from kabuli chick pea seeds on functional properties obtained by tow extraction method includes alkaline extraction and acidic extraction was investigated. In research protein extraction had to pH=2.5 and pH=9.5 and followed by Isoelectric precipitation (pH =4.5). Functional properties of Kabuli chickpea protein isolates such as oil absorption capacities, water absorption capacities, foaming capacity and stability, emulsion capacity and stability were evaluated. All experiments were performed in triplicate and Duncan multiple range tests with a confidence interval of 95% was used to compare the means. Results showed that; Isolates obtained by acid method had higher emulsification (capacity emulsion 87.77% and stability emulsion 87.92%), and foam properties (capacity foam41.42% and stability 57.16%) than alkalin method. While alkalin method enhanced water absorption capacities (1.52 g/g) and fat binding capacities (1.68g/g). Whereas suitable functional properties of chick pea protein isolate could be used for substituting other proteins in food systems.

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Edible films and coatings are developed to improve quality and to extend shelf-life of food products. In this study, soy protein isolate was obtained from defatted soy flour by alkaline extraction and acid precipitation. Then edible films were prepared from soy protein isolate. The effects of protein concentrations and two plasticizers of glycerol and sorbitol on some physical and mechanical properties of the films were evaluated, using response surface methodology (RSM). The results showed that  tensile strength, opacity, thickness and water vapor transmission rate (WVTR) were increased, while elongation of the films decreased by protein concentration. Increasing the concentration of glycerol and sorbitol increased WVTR, elongation, total color difference (ΔE), thickness and opacity, while declined tensile strength of the films. The model developed by RSM for the physical and mechanical properties of the films had high coefficient of multiple determination (R² >0.87) and significant F values. The models suggested that the concentration of soy protein and the type and concentrations of the plasticizers are the most influential factors with significant effects on the properties of soy protein isolate films.

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  The purpose of this study was production of fish protein isolate and surimi from silver carp (Cyprinus carpio) and investigation of color characteristics as well as some chemical changes of their gel and powder. In this research, proteins were isolated using pH shifts method. Acidic pH (2.5 and 3.5) and basic pH (11 and 12) were used to produce fish protein isolate. Three steps of washing cycles were used for surimi production, which in the third step 0.2 % NaCl was used for more dehydration. Results showed that the product efficiency for fish protein isolate was significantly (P<0.05) more than that for surimi. Furthermore, the produced fish protein isolate using acidic pH had the most production efficiency amongst the samples. As a result, fish protein isolate had more recovery protein content compared to surimi. Determination of fat content of the samples showed that surimi contained significantly (P<0.05) lower reduction in fat compared to fish protein isolate. Investigation and comparison of color characteristics (L, a, b) attributed to gel and powder forms of the samples demonstrated that the produced fish protein isolate using pH 2.5 had the most intensity of lightness (L parameter) amongst the other samples. This study clearly showed that the production efficiency of fish protein isolate was higher than surimi.  In addition due to soluble proteins elimination in the process of surimi production, fish protein isolate had more protein content. The more reduction in fat content of fish protein isolate can be considered as an advantage because of possible increase in durability and safety of the products.  

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The present study was conducted with the aim of protein isolate production from the muscle of grass carp (Ctenopharyngodon idella) and investigation of the effect of extraction pH on different properties of isolated protein. Proteins were produced by pH-shift method in two treatments including dissolution in alkaline pH (11.5), and acidic pH (3), and then evaluated in terms of nutritional value, functional properties, and structural changes. According to the results, the yield of protein production was significantly higher in alkaline conditions than in acidic conditions. The evaluation of emulsifying and foaming capacity and water absorption capacity showed that the protein obtained from alkaline pH was better than acidic treatment. Also, the extracted proteins contained all essential amino acids within the recommended limit for daily consumption of adults. The evaluation of color indices showed that the protein obtained from acidic pH had a brighter and whiter color than alkaline pH. The images obtained from the scanning electron microscope and the FTIR spectra of samples showed that the pH-shift method did not lead to extensive destruction of the protein structure and both protein isolates had all the absorption peaks related to the main bonds of the proteins structure. In general, it can be concluded that the pH-shift method is an efficient method for extracting high quality protein from grass carp tissue, and different alkaline and acidic conditions lead to the production of proteins with different characteristics that can be used based on the application that is intended for the final product.

 

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The aim of this study was production of fish protein isolate (FPI) and surimi from a low cost and underutilized fish species, carpio (Cyprinus carpio), and investigation of their gel textural properties. FPI was prepared by pH shifting at acidic (2.5 and 3.5) and basic (11 and 12) pHs. Surimi was prepared by 3 times water washing and at the third stage 0.2% NaCl was added to remove the water more efficiently. The results showed that production yield of FPI was significantly (P< 0.05) higher than surimi due to removal of soluble proteins during surimi production. Among the FPI, the FPI produced at acidic condition had higher production efficiency than the others. Protein recovery content of FPI was higher than surimi. FPI prepared at pH 11 showed harder textures compared with the others. Production of hard texture and easy preparation process of FPI compared with surimi were other findings of this study.    

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Mayonnaise is a kind of oil in water emulsion, that most widely used sauce in the world. Egg yolk is a key ingredient in mayonnaise, due to excellent emulsifying properties. Nevertheless, one main problem with egg yolk is its high cholesterol content, so different attempts have been carried out to develop low cholesterol mayonnaise. The aim of this study was to prepare low cholesterol mayonnaise containing wheat germ protein isolate (WGPI) and xanthan gum (XG) as egg yolk substitutes. The mayonnaise prepared with different composition of WGPI, egg yolk (0-9% of each component) and XG (0-0.5%), as formula variables by applying the optimal mixture design approach. Effect of this substitution on rheological characteristics and microstructure of mayonnaise samples were evaluated. The results indicated that all mayonnaise samples exhibited thixotropic shear thining behavior under steady shear tests, which fitted by Power law model and the factors related to this model were specified in the samples. Also, it was observed that mayonnaises exhibited weak- gel like properties, by using dynamic oscillatory shear tests and had significant effects on acquired parameters from frequency sweep test, such as storage modulus, loss modulus and tan delta. According to rheological and microstructure results, the low cholesterol mayonnaise contained WGPI and XG shows similar characteristics to those of a typical mayonnaise. Formulation 10 (71.5% and 4.2% egg replacement with WGPI and XG, respectively) shows the most similarity to control sample.  

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Wheat flour has many proteins in which gluten is an important protein in it and this protein has important role in dough formation and bread making.Thus, Uses of different materials must be considered to improve gluten quality as well as wheat flour enrichment. In this study the effects of adding chickpea protein isolate in range of 3 to 7 g and ascorbic acid in  ‎range of 0.05 to 0.15 % in wheat flour formulation on gluten stability and extensibility were investigated by response surface methodology. Therefore, The results showed that  increasing of chickpea protein and ascorbic acid concentration had significant effect (p<0.01) on farinograph parameters texture analyzes (dough extensibility) . The results of optimization in the case of 3 gr of chick pea protein isolate and 0.15% of ascorbic acid were as follows; water absorption 57.7%, dough development time 2.8 minute, dough stability 6 minute, mixing tolerance index 58 FU, farinograph quality number 91.3, toughness (area under curve) 3.3 N/mm, maximum resistance 0.02 N and dough extensibility 22.9 mm. Therefore, chickpea protein weakens strong flours gluten and it can be uses for making biscuit .   

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There has been a renewed interest in edible films made of renewable and natural polymers such as protein, polysaccharide and lipids. Natural polymers derived from natural sources like food protein, offer the greatest opportunities because of their biodegradability and their ability to supplement nutritional value of foods. Faba bean is a valuable source of protein and is cultivated in large quantities in Iran. Therefore, in this study, we investigated the potential of faba bean protein isolate (FPI) as a new protein source for preparation of an edible film and determined the effects of film forming solution pH and plasticizer concentration on the film properties. Results showed that increasing the pH improved mechanical properties (tensile strength and elongation) and solubility of the films, but, caused the water vapor permeability (WVP) and lightness of the films to decrease. Plasticizer concentration did not affect WVP over the studied range. Elongation and solubility of the films increased and the tensile strength decreased by increasing plasticizer content of the film forming solutions. The lowest WVP and the highest tensile strength were observed at pH 12 and 40% (w/w of FPI) glycerol concentration.

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In the present study, the fish protein isolate (FPI) of wastes of Siberian sturgeon (Acipenser baerii) has been substituted with fish minced (10, 20, 30, and 40%) in preparing fish nuggets. After preparing fish nuggets (88% Silver carp fillet) and initial cooking, the parameters such as approximate analysis, product yield, weight loss, pick-up, microbial growth, and sensory evaluation were investigated. The results showed that the lowest amount of moisture is related to the IP40 Group and no significant difference exists between other treatments. In comparison, the amount of protein in the control sample was the highest (18.00 ± 0.04) and it was decreased with the increase of FPI substitution (P<0.05). The highest amount of weight loss during final cooking was related to the control and IP10 treatments, and the highest product yield was associated with IP20, IP30, and IP40 treatments (P<0.05). The microbial growth results did not show any significant difference among the treatments (P>0.05). Moreover, the sensory evaluation showed the control group, which was only with fish minced, had better taste, smell, texture, etc. than the treatments containing isolated protein. The results of this research showed that the minced fish of silver carp and the FPI by-product can be used to produce fish nuggets, and although in some physical properties, the nuggets containing higher amounts of isolated protein have shown better results, according to the amount of protein and sensory evaluation, the control and the sample containing %10 FPI had better results.

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The effect of xanthan gum (0-0.3%) on corn oil-in-water (pH=7) emulsions prepaired by 0.5% grass pea (Lathyrus sativus) protein isolate was studied. Particle size, PDI, zeta-potential, emulsion capacity, emulsion stability and creaming index of emulsions were measured inorder to find the effect of xanthan gum on the stability of emulsion. Results showed that increasing concentrations of gum caused depletion flocculation and thus increased the particle size but had no significant effect on the zeta potential. Study on creaming index, emulsion capacity and stability also showed that with increasing xanthan gum, emulsion capacity and stability increased, while, creaming index decreased. Therefore, after 28 days of storage at 4˚C, no changes were observed in the emulsions containing xanthan gum.

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Increasing soy protein isolate content may be a practical and cost-effective means to control the functional properties of imitation pizza cheese. Imitation cheeses containing 2, 3 and 5% (w/w) soy protein isolate as a partial caseinate substitute were manufactured and dynamic rheology of these products were compared to a control (0% w/w soy protein isolate) in temperature sweep analysis. The dynamic rheological properties of caseinate-based imitation cheeses containing various concentrations of soy protein isolate were investigated using a strain-controlled rheometer. The storage modulus (G’), the loss modulus (G”) and the loss angle (Tan‌) were measured as a function of temperature (35–100°C). The storage modulus and loss modulus of imitation cheeses was significantly decreased (P0.05) at all examined temperatures (35–100‌) with the inclusion of soy protein isolate. Inclusion of soy protein isolate significantly increased imitation cheese peak Tan‌ values compared to control (P0.05), and the inclusion of 5% (w/w) soy protein isolate as a partial caseinate substitute had the greatest effect. In sensory evaluation, in terms of texture and mouthfeel, flavour and total acceptance the highest score belonged to control, while in all of samples lowest score observed in sample containing 5% w/w soy protein isolate. The results of this study showed that varying the level of soy protein isolate altered dynamic rheological properties as a function of temperature and thus the functionality (for example, meltability), as well as sensory attributes of imitation pizza cheeses.

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The present research work was aimed to evaluate  the effects of whey protein concentrate (WPC) at different levels of  0, 2, and 4%, as a protein based fat replacer, soy protein isolate (SPI) (0, 1, and 2%) and microbial transglutaminase (MTG) (0, 1, and 2%) on some physical properties of  a low fat  vanilla ice cream (4% fat). Electrophoresis pattern of ice cream proteins and effect of MTG on proteins were analyzed by SDS-PAGE. Total solids of all formulations was adjusted on 34%. Results showed that application of WPC in formulation of low fat ice cream significantly  increased  hardness and melting values, while SPI significantly (P<0.01) increased  hardness and reduced melting value. MTG decreased hardness and melting of ice cream samples compared to the control (P<0.01). Results showed that application of MTG in low fat ice cream was more useful than the utilization of SPI and WPC in terms of hardness and melting properties.

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Optimum utilization of animal protein byproducts results in the use of maximum production capacity in existing processing plants. The purpose of this research was to develop a new and ready-to-eat product from fish mince and chicken protein isolate with desirable sensory characteristics by using the D-optimal Mixture Design, Quantitative Anatomical Analysis (QDA), and Principal Components Analysis (PCA ). Initially, 13 prototypes containing different percentages of fish mince and chicken protein isolate (totaling 70% of the product formulation) were prepared. After sensory evaluation by QDA method, a prototype was selected as the optimum treatment, which included 50% fish mince and 20% chicken protein isolate and 30% other ingredients. The sensory stability of the optimum prototype was investigated in comparison with the control treatment during 90 days of frozen storage. Physicochemical analysis (pH, TVB-N, PV and TBARS) and microbial tests were also used to investigate the qualitative changes of the prototypes. The results showed that the optimum prototype had better sensory and quality indexes than the control sample. This study introduces chicken protein isolate as a new food ingredients. It also emphasizes the use of a combination application of QDA and PCA analysis and the D-optimal Mixture Design model in designing and manufacturing a product with the optimal formulation. Because these data will be applicable and valid for industrial scale production.