Food Technology
Ali Hashemi; Jafar Milani; Ali Motamedzadegan; Sepide haghighat
Abstract
Introduction: Due to the low amount of prolamin, rice flour is the most suitable raw material for preparing food for patients with celiac disease. Particle size classification and thermal treatments are among the physical methods to improve the functional characteristics of gluten-free flours and as ...
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Introduction: Due to the low amount of prolamin, rice flour is the most suitable raw material for preparing food for patients with celiac disease. Particle size classification and thermal treatments are among the physical methods to improve the functional characteristics of gluten-free flours and as a result, improve the quality of the products obtained from them. Particle size can increase the quality of gluten-free products by affecting the physicochemical properties of flour during hydration. Dry heat treatment and moist heat treatment are common techniques for physical modification which, depending on the intensity of temperature and storage time, lead to the improvement of gluten-free products by modifying starch grains, aroma, and flavor, and reducing microbial load. Considering that the effect of rice flour particle size on the quality of gluten-free bread has not been studied so far, in the current research, by dividing rice flour into particles with sizes of 180, 150, and 125 microns and using moist and dry heat treatment, it is possible to Improving the functional characteristics of rice flour and improving the quality characteristics of gluten-free bread were investigated. Materials and Methods: The content of moisture, pH, ash, and protein of rice flour was measured using AACC standard method (2000) and the total amount of starch was measured by the alkaline extraction method and the amount of starch damage was measured by non-enzymatic rapid method. To classify the size of the particles, waxy rice flour was divided by a shaker sieve with different sizes of 180, 150, and 125 microns, then under the influence of dry heat treatment for 2 hours and moist heat treatment with humidity, 25% for 5 hours at a temperature of 110 degrees. Celsius was placed. To produce gluten-free bread, the formulation used by Haghighat‐Kharazi in 2020 was used with a slight change. Ingredients for gluten-free bread formulation for 100 grams of rice flour included 125 ml of water, 4.5 grams of sugar, 2 grams of salt, 6 grams of vegetable oil, 3 grams of yeast, and 2 grams of xanthan gum. Bread tests, which include weight loss, specific volume, oven spring, Crumb crust ratio Shape index, porosity, crust and Crumb color, and bread texture analysis were studied to evaluate the quality of bread. Finally, the factorial test was used to investigate the effects of particle size and heat treatment of rice flour, and Duncan's multiple range test was used to compare the means at the 5% probability level.Results and Discussions: The results showed that the effect of particle size on weight loss, specific volume, oven spring, Crumb to crust ratio, crust, and Crumb color parameters, and bread texture was not significant (p>0.05). Regarding the sample volume index, C80 and DHT120 significantly had the lowest volume index (p<0.05). The HMT80-treated sample significantly increased the weight loss, and the moist heat-treated samples significantly increased the specific volume and the core to shell Crumb (p<0.05). In this study, the sample treated with HMT 120 had the highest volume index. moist heat treatment and dry heat significantly led to a decrease in brightness and an increase in the yellowness of the crust and Crumb of the bread compared to the control sample, but there was no change in the amount of redness (p<0.05). Moist heat treatment samples had the lowest hardness and Chewiness in this research compared to the control sample and the dry heat treatment sample. In general, the sample obtained from 125-micron particles and moist heat treatment led to the improvement of gluten-free bread quality.
Food Technology
Hoda Ghorbanzadeh; Jafar Milani; Ali Motamedzadegan
Abstract
IntroductionWith the growth of the population and more demand for obtaining food and supplying the required food, the interest in the cultivation and consumption of edible mushrooms has increased. Since 1990, the world has focused on the mushroom production industry. In recent years, mushrooms have become ...
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IntroductionWith the growth of the population and more demand for obtaining food and supplying the required food, the interest in the cultivation and consumption of edible mushrooms has increased. Since 1990, the world has focused on the mushroom production industry. In recent years, mushrooms have become one of the most important food and medicinal sources. One of the largest species of edible mushroom is button mushroom (Agaricus bisporus), which has high nutritional and medicinal value. Button mushroom has high nutritional value due to the presence of things such as fiber, carbohydrates, protein, amino acids, minerals, vitamins, etc., and it also has antioxidant, anti-cancer, and anti-diabetic properties. This food has shown good health properties for humans. The quality of button mushrooms is determined by their color, texture, and taste. Color is the first characteristic that is perceived by consumers. Browning is one of the main reasons for the loss of mushroom quality, which reduces the commercial value of mushrooms. One of the most used methods today is the use of edible coatings for perishable foods, these coatings almost prevent the penetration of oxygen, depending on the type of coating used, and reduce the loss of moisture during storage. Chitosan has functional characteristics such as antimicrobial and antioxidant properties, and as an edible film, it can be considered a very good carrier to be combined with antioxidant and antimicrobial agents.Materials and methodsTo make chitosan solutions, first, each type of chitosan (70% deacetylated, 80% deacetylated, 90% deacetylated, and 100% deacetylated) was weighed in amounts of 0.5g, 1g, and 2g. then it was dissolved in 100 ml of 0.5% acetic acid solution and stirred for 12 hours at a speed of 1000 rpm at room temperature to dissolve uniformly. After 12 hours, each sample It was centrifuged for 15 minutes at 6000 rpm at 25 °C to separate the undissolved material. Mushrooms were prepared freshly harvested, washed with water, and then excess moisture was removed. After sorting and screening in terms of size and approximate weight, the mushrooms were added to 0.5%, 1%, and 2% chitosan solutions without being sliced and were immersed in the solution for one minute. The control sample was immersed in 0.5% acetic acid solution for one minute. After that, the mushrooms were air-dried at room temperature for one hour, and at the end, their excess moisture was removed with a tissue. The mushrooms were placed in 18*14 size polyethylene zip-top bags and stored in a refrigerator at 4°C. The effects of chitosan coating on weight loss, mushroom color and browning index, enzyme activity, texture, and total phenolic compounds were studied.Results and discussionThe results indicated that in maintaining the amount of total phenol, controlling the peroxidase enzyme activity, the degree of firmness of the mushroom during storage and the amount of gumminess, the best treatment was chitosan with a deacetylation degree of 70%, while in controlling the weight loss, the activity of poly Phenol oxidase and sensory test, chitosan treatment with 100% and 90% deacetylation degree had better results, and in terms of browning index and texture, chitosan treatment with 80% deacetylation degree showed better performance. This study showed that the use of chitosan coating can be effective in maintaining the characteristics of edible mushrooms.ConclusionsThe spoilage of edible mushrooms happens in a short time, and the storage of mushrooms has become one of the most important things in mushroom production. Coating edible mushrooms is one of the suitable methods to increase the shelf life of edible mushrooms. In this research, chitosan with four degrees of deacetylation and three different concentrations was used as a coating for edible mushrooms. The results indicated that coating the mushroom with chitosan could delay the occurrence of spoilage and change its color or texture.
Mahya Ouraji; Mazdak Alimi; Ali Motamedzadegan; Shirin Shokoohi
Abstract
Introduction: In recent years, legumes have been highly considered as a good source of protein, fibers, minerals and other bioactive compounds in order to develop novel foods with improved nutritional properties. There is some evidence that legume consumption reduces the risk of diabetes, cardiovascular ...
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Introduction: In recent years, legumes have been highly considered as a good source of protein, fibers, minerals and other bioactive compounds in order to develop novel foods with improved nutritional properties. There is some evidence that legume consumption reduces the risk of diabetes, cardiovascular disease and some cancers. Vicia faba has about twice protein content as cereals and can be a good alternative to meat and protein-rich ingredients. It should also be noted that the amount of insoluble fiber is higher than soluble fibers in legume. Vicia faba belongs to the Fabaceae family .Vicia faba contains high protein (21-41% dry content of the bean), carbohydrates (51-68% dry content of the bean), fiber (5-5.8%), B-vitamins and minerals. Recently, the protein function of Vicia faba, especially its protein isolate, has been studied on a laboratory scale for use in food products, due to its good ability in hydration, solubility, emulsification, viscosity, and foam and gel formation. Research has also shown that the protein in Vicia faba has better ability to emulsify water and oil and foaming capacity and foam stability compared to bean and pea flour. The structural and functional properties of the protein isolates and concentrates of legumes such as Vicia faba are strongly influenced by their preparation, extraction and drying methods. One of the ways to improve extraction and optimization of protein properties can be ultrasound and an enzymatic controlled hydrolysis. Due to the importance of dietary fiber, various methods have been developed for their decomposition, many of which are very precise and special, some of which have high-purity enzymes and selectively release oligosaccharides and polysaccharides containing dietary fiber. In this study, the possibility of using ultrasound and limited enzymatic hydrolysis in order to produce value added product and increase the extraction efficiency and improve the functional properties of protein and fiber of Vicia faba, were evaluated. Materials and Methods: In this study, ultrasound and enzymatic hydrolysis were used to optimize extraction and modify physicochemical properties of protein and fiber of VaciaFaba. The proteins were affected by ultrasound at 200, 300 and 400 W for 15, 25 and 35 minutes, and the Alcalase enzyme 2.4 LFG at 0.15, 0.3 and 0.45% doses were extracted at 15, 25 and 35 minutes and the design of the treatments was done by Designer Express software. Solubility, oil absorption capacity, emulsification and zeta potential of protein samples were measured. Vicia faba fiber extraction under alkaline conditions was obtained from solutions of 0.0012, 0.012 and 0.12% sodium hydroxide until reaching pH 12, 11 and 10 and Termamy 2x enzyme was used for enzyme hydrolysis. Water retention capacity and rheological properties of Vicia Faba fiber samples were investigated. Results and Discussion: The results showed that the use of ultrasound and enzymatic hydrolysis had a positive effect on solubility, oil absorption capacity and emulsion properties of the protein samples. Zeta potential was also negative for all treatments, which indicates that the Vicia faba protein treatment solution contains more negative amino acids than positive-loaded amino acids. Among the fiber samples of the ViciaFaba, a fiber sample with a pH of 10 had the highest water retention capacity and G-level than the other two samples, indicating a more solid and elastic quality. Also, in all fiber samples, increasing cutting speed reduced the viscosity and the samples showed a dilution action with cutting or pseudoplastic.
Ali Motamedzadegan; Elahe Omidbakhsh Amiri; Mahboubeh Jamshidi; Tandis Khosravi rad
Abstract
Introduction: In industrial operations, a product is submitted to a range of shear rates. The knowledge of the changes in rheology with temperature, frequency and shear rate is needed to design the equipment of operations. The lemon juice is used extensively in the food industry. Information about rheological ...
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Introduction: In industrial operations, a product is submitted to a range of shear rates. The knowledge of the changes in rheology with temperature, frequency and shear rate is needed to design the equipment of operations. The lemon juice is used extensively in the food industry. Information about rheological and physicochemical properties is important for scale up and optimization of processes such as transport and storage of concentrated lemon in commercial applications. The aim of this study was toevaluate the rheological and physicochemical properties of the concentrated lemon produced using vacuum evaporator.
Materials and Methods: Lemon juice was concentrated to 25, 35, 45, 55 and 65 Brix by a rotary evaporator under vacuum at 65°C. The content of soluble solids in terms of brix using refractometer, pH, acidity in terms of citric acid, color in terms of a* , b* and L*, flow behavior and viscoelasticity as function of strain, frequency and temperature using rheometer were investigated. Mean comparison carried out using the least significant difference.
Results&Discussion: As brix increased, pH reduced and acidity increased. An increase in the concentration resulted in a decrease in L* and b* parameters and an increase in a* parameter. Enzymatic browning in this study could be ignored due to the sensitivity of enzymes to temperatures above 50°C. Millard's non-enzymatic browning (formation of hydroxyl methyl furfural and its polymerization) and the degradation of pigments might be a major contributor to color variation, although a decrease in moisture content and an increase in soluble solids are other reasons for darkening of color. Based on coefficient of determination (R2) and root mean square error (RMSE), we could state that the Newtonian and Bingham models had the best fit with laboratory data of the stress-strain obtained for the control sample with the 7Brix, and the samples with 25 and 35 Brix. Newtonian and Bingham viscosity increased as brix increased (p
Masoumeh Pourseyed; Ali Motamedzadegan; Jafar Mohammadzadeh Milani
Abstract
Introduction: Converting milk into milk powder increases its shelf life up to almost 1 year, without substantial loss of quality, even at ambient temperatures. Dairy powder is frequently used because of convenience in applications for transportation, handling, processing, and ease of product formulations. ...
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Introduction: Converting milk into milk powder increases its shelf life up to almost 1 year, without substantial loss of quality, even at ambient temperatures. Dairy powder is frequently used because of convenience in applications for transportation, handling, processing, and ease of product formulations. Functional properties of milk powder are important due to its wide range of applications, especially in bakery products requiring desirable texture and moisture content. These functional properties include emulsification, foaming, water absorption, viscosity, gelation, and heat stability. Fresh milk and milk products such as condensed or dried milk which have not been exposed to sufficient heat treatment are not suitable for good quality bakery products as properly heated milk, mainly due to the destruction of proteolytic enzymes by heat, denaturation and coagulation of the proteins, changes in the colloidal properties of the salt and alterations in the oxidation-reduction systems. Kirk (1971) has outlined a list of functional contributions provided by skim milk powder (SMP) in various bakery food products, such as increased absorption, buffering value, lactose color reaction, tenderizing effect, improved body and resilience of crumb. This is in agreement with the results showed by Pyler who added SMP to bread and cake affected. Pyler noted the advantages of lactose in food systems. Lactose mostly affect relative sweetness, browning reaction, protein stabilizing properties, alteration of crystallization patterns, flavor accentuation, selective fermentation, and has nutritional value.
Materials and methods: Yazdi cake was produced using baking wheat flour (from Golha factory), sugar (sucrose), hydrogenated vegetable shortening, baking powder, and baking soda. Eggs were bought the day before baking and refrigerated at 4°C. The dough was prepared in ratio of 30 % oil, 46 % sugar, 50 % water, 11.7 % eggs, 4 % baking powder and 1 % baking soda rather than flour. For improvements of flavor and taste, an equal value of vanilla was added to the whole dough formulations. Skim milk powder containing 1.5 % fat, 3-4 % moisture has bought from Pegah factory. 25 and 50 percent of skim milk powder was also added to the dough. Dough was prepared based on the method of double mixture steps and was baked at 180°C in oven for 30 min. Samples were vacuumed and kept at ambient temperature for further experiments
Result and discussion: The differences in specific volume and consistency of the dough values were found to be significant (p>0.01). According to Baeva studies, there is an inverse relationship between specific gravity and the entry air bubbles in the dough, so the sample with 50% had the lowest specific volume. The consistency of the dough increased significantly by increasing in SMP content (P
Narjes Damavandi Kamali; Amirreza Shaviklo; Ali Motamedzadegan
Abstract
Introduction: At least 60% of the estimated 300,000 metric tons of tuna that are processed in Iran areby-products which arebeingwasted and converted to non-human products as fish meal or fertilizers. Therefore, a major challenge facing the tuna canning industry is to find the new processes to utilize ...
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Introduction: At least 60% of the estimated 300,000 metric tons of tuna that are processed in Iran areby-products which arebeingwasted and converted to non-human products as fish meal or fertilizers. Therefore, a major challenge facing the tuna canning industry is to find the new processes to utilize tuna processing by-products (mainly dark muscle) into valuable foods. The characteristics of tuna dark meat (TDM) make it not acceptable for these industries. Therefore, the isolation of proteins from TDM for food application would be a more responsible way of using a nutritious and abundant rest raw material.The pH-shift technology for recovering fish proteins involves the solubilisation of chopped and homogenized fish flesh either in an aqueous acidic or alkaline solution. The protein rich solution is separated from solids (insoluble proteins, skin, bones, and scales) and neutral lipids by centrifugation. The soluble proteins are then recovered by isoelectric precipitation by adjusting the pH to 5.5 and the precipitated proteins are removed by centrifugation. This method can be potentially applied with any white/ dark muscle fish or fish by-products. No evidence can be foundon isolation of protein from TDM. Therefore, this study was carried out to investigate stability and functional properties of proteins recovered from TDM. Materials and methods: The ground TDM was homogenized for 1 min (speed 50) with 9 volumes of ice-cold distilled water. The proteins in the homogenate were solubilized by dropwise addition of 1 N HCl or 1 N NaOH until the intended pH (2.5, 3.0 and 3.5or10.5,11.0 and 11.5) was reached. The protein suspension was centrifuged. The soluble proteins were precipitated by adjusting the pHs to 5.5 using 1 N NaOH or 1 N HCl. Precipitated proteins were collected via a second centrifugation. Proximate analysis of tuna protein isolates (TPI) was carried out. TBARS, pH, viscosity, water holding capacity (WHC), gel strength, biting and folding tests, texture profile analyses (TPA), and color were measured. Qualitative protein analysis was carried out using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE).Results and discussion: The protein, fat and moisture contents of the acid-aided protein isolates were found to be 28.65, 5.35 and 74.36% respectively. While alkaline-aided protein isolates contained 29.57% protein, 4.17% fat and 71.23% moisture. A significant difference was found in TBARS level between the isolated products. The lowest TBARS value was found in acid-aided isolate and isolate treated at pH 11.5. The TBARS value of isolates extracted at pH 10.5 and 11 was 0.15 mg malondialdehyde / kg, which was below the border line recommended for fish products. Lipid oxidation in fish protein isolates has been reported during pH-shift process. The lipid content of TPI samples and activating of haem proteins as prooxidants at different pH may describe lipid oxidation in TPI samples. The average viscosity of TPIs was 3.81 cP (Centipoise). The highest viscosity scores were observed for the isolates prepared at pH 11.0 followed by the isolates made at pH 3.5 and 11.5. The isolates treated at pH of 2.5, 3.0 and 10.5 had the same level of viscosity. Low viscosity might be due to low cross linking degree of protein molecules. The low viscosity of the prototypes may possibly be explained by decreasing interaction between proteins and the surrounding medium. Therefore, denaturation and modification of protein conformation in tuna protein samples may have affected the viscosity.The WHC of the samples (12-16%) was similar to the proteins isolated from the other fish by-products. The highest value of WHC among TPIs was found for the isolates prepared at pH 3.5. The rest samples had the same value of viscosity. The WHC can be defined as the ability of a protein gel to retain water against a gravitational force. The level of water retained in a gel is affected by the same factors that affect the formation of a good protein gel ‘i.e.’ moisture, pH and salt. Furthermore, the WHC usually reflects the extent of denaturation of the protein and water contents. It has been reported that WHC is closely related to fish species, amount of salt, different processing method and the interaction between these factors.The highest scores for gel strength, biting and folding tests and TPA (hardness, cohesiveness, springiness and resilience) were observed in TPIs treated at alkaline pH. The muscle proteins being particularly responsible for gelation are myosin and actomyosin. It has been reported that alkali-aided protein extraction caused less denaturation than an acid-aided process. This lower denaturation of proteins leads to products with enhanced texture. Hardness and cohesiveness were found to be maximum for samples prepared at pH of 11.5. The increase in hardness may also be due to the stronger gel network formed by the concentrated myofibrillar proteins in the protein isolates. The difference between TPA parameters of the recovered proteins andthe TDM mightbe due to the difference in lipid and collagen content.The alkali-aided process recovered proteins of higher whiteness than the acid-aided process possibly due to high removal amount of myoglobin and haemoglobin during leaching. The electrophoretic patterns revealed the stability of proteins in alkaline pH. The lowest reduction in band intensity of myosin (myosin heavy chain) and actin was found when the alkaline-aided process was applied. Accordingly the highest band intensity of myosin and actin proteins was observed at the high pH (11). The weak bands of protein among acid-aided samples have possibly been due to the hydrolysis effect of enzyme activity.
Ali Taheri; Abdolmohammad Abedian Kenari; Ali Motamedzadegan; Mehran Habibi Rezaie
Abstract
Protein hydro-lysate was prepared from Gold striped sardine (Sardinella gibossa) by Papain. Hydrolysis conditions (time, temperature, and enzyme activity) were optimized by response surface methodology (RSM) using a factorial design and anti-oxidative activity was the dependent variable. Results of the ...
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Protein hydro-lysate was prepared from Gold striped sardine (Sardinella gibossa) by Papain. Hydrolysis conditions (time, temperature, and enzyme activity) were optimized by response surface methodology (RSM) using a factorial design and anti-oxidative activity was the dependent variable. Results of the total determination coefficient, adjusted R2 and predicted R2 indicating the validity of prediction model and the experiment error was very small. An enzyme activity to substrate ratio (X1), 2%; time (X2), 30 minute, and temperature (X3), 45 °C were found to be the optimum conditions for a higher DPPH free radical scavenging activity (64.5%), using Papain. According to amino acid analysis results and chemical score, methionine and Isoleucine were the limiting amino acids in the hydro-lysate. The protein hydro-lysate tends to be a functional additive in food industries.
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.
Masoud Rezaei; Ali Motamedzadegan
Abstract
To investigate the optimum conditions for extracting gelatin from whitecheek shark (Carcharhinus dussumieri (skin, response surface methodology (RSM) has been adopted. In this research, the effect of NaOH concentration (0.01-1 N), HCl concentration (0.01-1 N), and extraction time (3-8 h) on dependent ...
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To investigate the optimum conditions for extracting gelatin from whitecheek shark (Carcharhinus dussumieri (skin, response surface methodology (RSM) has been adopted. In this research, the effect of NaOH concentration (0.01-1 N), HCl concentration (0.01-1 N), and extraction time (3-8 h) on dependent variables, yield and melting point of the skin gelatin have been studied using central composite design. Based on the individual regression models, predict values of multiple response at optimal condition were %23.222 (yield), and 32.224 °C (melting point). The best pretreatment conditions to get to the optimum properties were 0.01 N NaOH, 0.135 N HCl and 3 h extraction time. The results showed that, NaOH and HCl concentrations had significant effects, but extraction time had no significant effect on gelatin extraction yield and its melting point.
Maryam Modanlow; Gholamreza Rafiee; Ali Motamedzadegan; Sohrab Moeini; Alireza Mirvaghefi; Mahmoudreza Ovissipour
Abstract
In present paper the optimum extraction condition of protein of Hydrolysate from the viscera of yellow fin tuna (Thunus albacores) were studied. Enzyme hydrolysis has been performed at enzyme to substrate ratio: 1.3-3.7 mg/gr.protein , time of reaction: 1-10 hours, temperature: 30-44 ºC and using RSM ...
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In present paper the optimum extraction condition of protein of Hydrolysate from the viscera of yellow fin tuna (Thunus albacores) were studied. Enzyme hydrolysis has been performed at enzyme to substrate ratio: 1.3-3.7 mg/gr.protein , time of reaction: 1-10 hours, temperature: 30-44 ºC and using RSM method and central composite design(CCD) with 4 repetitions at central point and five levels of each treatment. Results have been compared with average at statistical level where α = 0.05. According to results,the protein recovery increases with an increase in enzyme activity from 1.3 to 2.5 mg When enzyme activity increases to 3.35 mg, the protein recovery reaches a constant level and then decreases with an extra increase of enzyme amount to 3.7 mg.The rate of protein recovery increases, With an increase in temperature from 30 ºC to 37 ºC,And then the enhancement of recovery rate decreases with more increase of temperature from 37ºC to 42ºC, However it will remain constant for temperatures beyond 42ºC.The protein recovery decreases With increasing the hydrolysis time between 60 to 138 min. and it reaches a stationary phase somehow during 138 to 330 min.In optimum point of hydrolysis, protein recovery was 75%. This condition were observed in enzyme ratio of 2.41 mg ,Temperature of 38.75ºC,and hydrolysis time of 570 min. Results showed that protein recovery is mainly influenced by ratio of enzyme to substrate rate and temperature ,while time of hydrolysis should be considered as a function of temperature and enzymatic ratio.
Keywords: Protein hydrolysate, Protein recovery, Optimization, Waste of yellow fine tuna, Trypsin
Ali Taheri; Abdolmohammad Abedian Kenari; Ali Motamedzadegan; Rajab Mohammad Nazari
Abstract
In current study, protein hydrolysates were produced using microbial proteases of Alcalase, Protamex and Flavourzyme from Yellowfin tuna viscera. The results indicated that, protein hydrolysate from Alcalase, had significantly higher protein content, nitrogen recovery and degree of hydrolysis than the ...
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In current study, protein hydrolysates were produced using microbial proteases of Alcalase, Protamex and Flavourzyme from Yellowfin tuna viscera. The results indicated that, protein hydrolysate from Alcalase, had significantly higher protein content, nitrogen recovery and degree of hydrolysis than the others (P0.05). The results of amino acids composition revealed that all hydrolysates were almost similar in amino acids composition. In addition, the protein efficiency ratio (PER) showed that all hydrolysates had high nutritional value. The chemical score results showed that all hydrolysates could fulfill human amino acid requirements. While, in comparison with common carp requirements, the amino acids of methionine, lysine and phenyl alanine, were the limiting amino acids in all hydrolysates. According to the results of this study, Alcalase is the most affective enzyme. Also, Yellowfin tuna hydrolysates have high nutritional value, that can be used as protein source in diets.
Key words: Tuna fish, Enzymatic hydrolysis, Commercial enzymes, Nutritional value
Elham Khanipour; Javad Keramat; Seyed Hashem Hosseiniparvar; Ali Motamedzadegan; Azadeh Ghorbani; Seyed Ahmad Shahidi Yasaghi
Abstract
Carotenoids are the main pigments of tomato, of which 93% is lycopene. Lycopene has desirable physiological effects in human sush as cancer prevention. Recent years, because of harmful side effects of synthetic colouring agents used in food products, employing of natural food colouring agents has become ...
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Carotenoids are the main pigments of tomato, of which 93% is lycopene. Lycopene has desirable physiological effects in human sush as cancer prevention. Recent years, because of harmful side effects of synthetic colouring agents used in food products, employing of natural food colouring agents has become very important. In this research firstly, solvent extraction method was used for tomato carotenoids extraction. The optimum conditions for solvent extraction method was a mixture of solvent (n-hexan, ethanol and acetone with ratio of 1:1:2), boiling temperature (50 ºC), extraction time of 6 hours and equal ratio of solvent volume to tomato sqwash (crushed tomato after removing of skin and seeds). After extraction of tomato carotenoids, applicability of the extracted colour was considered by using the colour in sausage (13.977, 9.501 and 7.03 gr colour per 100 Kg sausage) and ice cream (4.21, 8.42 and 12.63 gr colour per 100 Kg ice cream). The best percentage of the added colour to those products were determined by performing of a taste panel. Finally, the stability of the colour in the products was examined by storing them at 0-4ºC (for sausages) and -21ºC (for ice cream) and their colour changes were measured by Hunterlab Colorimetry System. Results of sensory evaluation showed that addition of 9.501 gr of extracted colour per 100 Kg susages and 8.42 gr of extracted colour per 100 Kg ice cream are acceptable for consumers. From viewpoint of colour changes of surface and cross section of susages, there was significant difference between first and second period of storage, but there was no significant difference between third and forth period of storage (P
