Iranian Food Science and Technology Research Journal

Abstract The rock candy is the grown sucrose crystal which has been produced in Iran and India for the first time originally. In this process, the large sucrose crystals has been produced by cooling the supersaturated solution. The traditional processing has not changed up to now. Recently, many efforts were done to optimize it. The production of rock candy evaluated under cooled crystallization process. To increase the yield and the growth of sucrose crystals, the supersaturation and crystallization parameters should be optimized. Due to low efficacy in this procedure, sucrose crystals with dimensions less than 3 mm are usually produced by evaporating crystallizers. In this research, traditional production process of rock candy is studied by doing experiments at different phases in a traditional plant. According to the results, it takes more than 90 min to reach the suitable supersaturation, an temperature (112°C) and extra evaporation. So the invert sugar content, reach from 0.015 % in original sugar to 0.571 % in effluent (mother syrup). The produced rock candy has 0.553 % invert sugar. The pH of solution decreases from 7.3 to 5.2, the color increased from 70 (in primary sugar) to 1240 ICUMSA unit in the effluent and more than 250 Iu in produced rock candy (measurement in λ = 420nm ). The high color rate and invert sugar cause the effluent can not be used in production process. Key words: sucrose, rock candy, crystallization, supersaturation.

Abstract Usage of different lactic acid bacteria strain is one of the reduction methods in phytic acid content of bakery products. In this study the effect of making sourdough with L. plantarum and L. reuteri with DY=160 and DY=200 and replacement ratio 10, 20 and 30% instead of flour in dough formulation on phytic acid content of Lavash bread was investigated. The highest decrease in phytic acid content is related to using sourdough involved L. plantarum with DY=200 and 30% replacement of sourdough (44.06%). Usage of sourdough causes flavor and chew ability modification in bread. The best flavor is related to bread which is made of sourdough involved L. plantarum with DY=200 and 30% replacement. But biophysical properties containing texture, form, shape, and up and down surface in this sourdough application gain lower score than bread which is made of yeast. Keywords: Phytic acid, Lavash bread, Lactobacillus plantarum, Lactobacillus reuteri

Abstract The demand for low fat snacks is increasing. There are different methods to produce low fat fried products. One of these methods is coating. In this study effect of Carrageenan, oil temperature and frying time, on oil uptake of fried products (chips and strips) has been evaluated. Samples were deep fried in frying oil (Palm olein) at 160, 175 and 190 ºC. In order to evaluate the effect of frying time on oil uptake, potato strips coated with 1% Carrageenan were fried for 1 to 10 minute, then oil uptake has been measured. Results showed that Carrageenan as a hydrocolloid coating, reduced oil uptake in fried potato products compare with control samples. Coating potato slices with 1% Carrageenan led to significantly reduction in oil uptake (p

Abstract The preferred colour for surimi is white, but surimi prepared from light fillets of common carp (Cyprinus carpio) is slightly pink. Hydrogen peroxide (H2O2; 1-3% v/v) with and without sodium tri-polyphosphate (STP; 1-2% w/v) was added to a sodium carbonate bath (pH 7.0-11.5) resulting in a final pH range of 4.4 to 10.1 which was injected into carp fillets. After soaking and tumbling for 30 min at 4-10ºC, the fillets were evaluated for colour and water holding capacity (WHC). Fillets tumbled with treatment solution at different pH levels (7.0-11.5) without H2O2, had improved colour with significantly (P < 0.05) higher L* compared with untreated fillets as the control. However, the colour improvement [(L* and colour deviation (ΔE)] was not significantly different (P > 0.05) within the pH levels (7.0-11.5) trialled. With increasing H2O2 levels (1-3%), fillets became lighter and ΔE increased significantly (P < 0.05), especially with a 3% H2O2 treatment at pH of 10.5. The whiteness (L*-3b*) of surimi produced from treated (3% H2O2, pH 10.5) common carp fillets was compatible with that of Alaska Pollock and significantly (P < 0.05) higher than that of surimi from threadfin bream. On the contrary, WHC of treated fillets and its resultant kamabok gel significantly decreased in comparision with other samples. This was investigated by scanning electorn microscopy (SEM) technique. It was concluded that application of 3% H2O2 has possibly denatured the myofibrillar proteins which caused lower number of polygonal structure at the gel matrix of kamaboko prepared from treated fillets. It is recommended to improve the colour of common carp surimi while keeping the myofibrillar proteins intact by application of lower concentration of H2O2 on either chopped fillets or mince. Keywords: Hydrogen Peroxide, Surimi, Colour, Water holding capacity, Microstructure

Abstract The main aim of this study was to improve the bread quality and to postpone its staling. Therefore, sugar beet pulp powder was added to Barbari bread dough formulation at five levels of 1, 3, 5 and 10% (w/w, flour basis). Then the properties of dough and the resulting bread were studied. The results showed that with increasing the sugar beet pulp powder, the water absorption of the dough and the fiber content of the bread increased while, bread density and hardness decreased. The electro-micrographs of the bread crumb containing sugar beet pulp powder indicated the improved texture which can delay bread staling. Sensory evaluation of the samples revealed that the bread made with up to 5% sugar beet pulp powder had the highest general acceptability. However, higher levels of sugar beet pulp powder had diverse effects on bread color which would reduce general acceptability of the samples. It was concluded that sugar beet pulp powder can improve the quality of bread and delay its staling. Keywords: Sugar beet pulp, Dietary fiber, Bread staling, Bread texture

Abstract Novel edible emulsified films were made using pistachio globulin protein (PGP) and palmitic fatty acid at concentrations of 2, 4, and 6 % w/w protein by Tween-80 and homogenization technique. Addition of palmitic acid to the PGP filmogenic solution resulted in great reduction of WVP in the emulsified films (37-40 %). Concentration of palmitic acid did not create significant difference (P>0.05) among WVP of the emulsified films. The WVP decreased as function of palmitic acid concentration. Water solubility of PGP films was 44.8 % and slightly decreased in the emulsified films. Oxygen permeability of the emulsified films were lower than the PGP films, but the differences were not significant (P>0.05). Tensile strength and elongation at break of the emulsified films were diminished as a result of palmitic acid addition. Incorporation of palmitic acid led to produce the opaque films, which opacity increased as function of palmitic acid concentration. Glass transition temperature (Tg) was determined by differential scanning calorimetry. The Tg of the PGP film revealed at 127.19 °C and was not affected by palmitic acid. Keywords: Pistachio globulin protein, Palmitic acid, Gas permeability, Elongation, Tensile strength

Abstract Silver carp is the major specimen in warm water fish culture system in Iran which is presented in various size and different price. The present study was aimed to compare nutritional value and to investigate proportion of nutritional value and financial of various weight groups of silver carp in spring season. For this purpose silver carp was prepared in market sizes and their dry matter, fat, protein and ash content and fillet yield were determined and the indices of proportion of nutritional value and financial (NP) and justified price difference based on dry matter content (PDdm) were calculate for weight groups. According to obtained results, the more heavy weights of silver carp contain lower moisture but higher fat and energy (p0.05). Light weight group has a higher (p0.05), except fat (p

Abstract Nowadays, quality control of bread, especially in large scale production, requires application of novel methods. In this research, image analysis of digital images of Barbary bread enriched with soy flour was carried out at two storage intervals. Using Imagej software, crumb features (mean cell area and void fraction) were computed for each image. Fractal dimensions of bread crumb images were measured using Fourier transform method with a code written in Matlab. Contrast, energy, correlation and homogeneity of images also were measured and statistically analyzed. Storage time had significant effect on fractal dimension and void fraction, also resulted changes in textural parameters of bread images. The deduction of this work could be regarded as rapid, non-destructive, objective and inexpensive method for quality evaluation of bread crumb. Keywords: Barbary Bread, Fractal dimension, Image analysis, Soy Flour

Abstract This study was done to evaluate quality properties of Pistacia atlantica var mutica (Bene) nuts under deferent storage conditions and packaging. At the zero time, SFA and Total tocopherol (TT) and Total phenolic (TP) compounds were 6.8 and 725.28 and 40.1 mg per kg oil, respectively. Some quality properties (Peroxide value (PV), Conjugated diene value (CDV) and Carbonyle value (CV)) showed that a limit oxidation was done in the Bene nuts, too. The PV and CDV values of different packaged Bene nut samples during the storage time (12 weeks) didn’t have significant differences (p< 0.05) in the 20, 30 and 50°C but decrease of TT and TP compounds were significant (p< 0.05) under such circumstance. The most amount of degradation of TT compound was 17.9%. Therefore, many of these compounds remained at the end of storage time (12 weeks). The antioxidative effect of these components resulted in low variation in the PV and CDV values at the end of storage time in above mentioned temperatures. The packaging of Bene nut samples by PET/AL/LLDPE multilayer plastic bag was best because of the lowest degree of permeability to oxygen. Keywords: Bene nuts, Packaging, Fatty acid composition, Total tocopherol, Peroxide value, Conjugated diene value, Total phenolics, Carbonyle value

Abstract Yog-ice cream (Frozen yogurt), is a kind of frozen dessert which has similar features to ice cream in physical and appearance characteristics. Recently, there has been a growing interest in using frozen yogurt due to existence of lactic acid bacteria & fermentation processing. Besides, yog-ice cream contains lower levels of sugar, fat & emulsifiers than ice cream. This Research was conducted to examine the effect of date syrup with different concentrations (0, 25 and 50% as a sugar replacement) & guar gum addition (0, 0.1, 0.2 & 0.3% as a fat replacer) on rheological properties of low fat orange yog-ice cream. The results showed that by increasing the date syrup and guar concentration, the viscosity of mixture increased but overrun decreased significantly in all samples (p< 0.05). Results for stickiness of the yog-ice cream samples indicated that the low fat yog-ice cream was considerably less adhesive/sticky than both low fat product containing guar and date syrup. Hardness of low fat yog-ice cream samples was observed to be considerably higher than the samples with guar and date syrup, whilst the addition of guar and date syrup up to 0.3% & 25%, decreased the hardness of the low fat product. Keywords: Low-fat yog-ice cream, Guar, Dates syrup, Rheological properties

Abstract In this study the effect of different levels of xanthan and pectin on water activity and sensory properties of fruit pastille formulation based on Cantaloupe puree has been studied. The effects of xanthan (0, 0.1, 0.2, 0.3 %) and pectin (0.2, 0.3, 0.4, 0.5 %) were analyzed in a completely randomized design with factorial experiment. Results of ANOVA revealed that different levels of xanthan, pectin and interaction effects between pectin and xanthan had significant influence on water activity of cantaloupe pastilles (p≤0.05). The effects of pectin and xanthan were evaluated on sensory attributes by using multivariate variance analysis (MANOVA). Generally, only pectin level significantly changed (Hotelling Trace = p≤0.05) the sensory attributes. Pectin showed significant influence (p≤0.05) on color intensity, flavor color and appearance acceptance of pastilles. Xanthan had significant effect (p≤0.05) on color intensity and surface adhesivness. Pectin-xanthan interactions also showed significant influence (p≤0.05) on color intensity and stiffness of pastilles. Results of PCA determined that texture and flavor properties were more important than appearance attributes on total acceptance of cantaloupe pastille. Keywords: Fruit pastille, Cantaloupe, Sensory properties, Water activity, Principal Component Analysis

Abstract The aim of this research was to use ultrasound pre-treatment and studying the time of drying and rehydration in dried samples of kiwifruit (Hayvard variety). The samples were dehydrated for different lengths of time, 10, 20 and 30 minutes at room temperature in distilled water in Ultrasound bath (45 kHz). The results of drying time showed that by decreasing the thickness of samples from 8 to 6 mm and increasing the ultrasound time, the time required reducing the moisture content down to 20% for each treatment. It was also found that the minimum time for bringing the moisture down to 20% in 6 and 8 mm kiwi fruits in pre-treated samples with 30 minutes sonication time was 299 and 404 minutes, respectively. The results of rehydration in samples showed that by increasing the time of sonication and decreasing the kiwifruits samples thickness from 8 to 6 mm, the rehydration increased compared to control sample. The results of organoleptic valuations about to totality acception of dried kiwifruit product showed that using pre-treated ultrasound sample was more acceptable than the control sample. Keywords: Rehydration, Drying, Kiwifruit, Ultrasound

Abstract Soy protein concentrate (SPC) is a functional and nutritional product which is produced under conditions where soy proteins are immobilized in soy flour and soluble carbohydrates are removed. In this study, four different soy flours including defatted soy flour (fat content 3.67, PDI 55.10), defatted and toasted soy flour (fat content 3.78, PDI 10.72), low fat soy flour (fat content 14.34, PDI 32.71), and whole soy flour (fat content 22.08, PDI 28.72) and two washing methods including alcohol washing and acid washing were used to produce SPC Then yield, changes in chemical and functional properties including PDI, dispersible solids, water holding and fat binding capacity, emulsifying and foaming properties were determined. The results showed that SPC from whole soy flour had higher yield and higher increase in fat content but presence of fat reduced protein concentration. Acid washing had lower production yield than alcohol washing due to better removalg of soluble carbohydrates but it increased fat and protein content. Functional properties of SPC from defatted soy flour was changed significantly during its process while fat content or heat denaturation occurred during toasting diminished its effect except for emulsification stability. During the process, water holding capacity increased specially in products with higher amounts of fat content. Although most of PDI changes arose from drying step, but the effect of processing on emulsification and foaming properties was much higher than drying.

Abstract Heart disease - cardiovascular, cancer and obesity are the main causes of death and there are direct relationship between the consumption of high-fat foods and the incidence of these diseases. Therefore the demand for low-fat food products and probiotics has been dramatically increased. In this study, the effect of different levels of three hydrocolloids (inulin, chitosan and xanthan) at three levels (1, 2 and 3%) on survival of Lactobacillus acidophilus, physicochemical and sensory properties of yogurt during 15 days of storage was explored using a combined design. Increased levels of inulin and chitosan positively affected La-5 count, apparent viscosity, acidity and sensory scores during storage. Using graphical method of optimizing (overlaid contour plots), optimum ratios were: inulin 93.4%, xanthan 0.6% and chitosan 6%.

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 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.

Abstract In view of the importance environmental pollution caused by plastic food packaging, in recent years there is a considerable interest in edible films and coating based on polysaccharides, proteins, lipids or combination of them. Edible coatings also serve as carriers of food additives such as anti-browning and antimicrobials agents, colorants, flavor, nutrients and spices, so act as active packaging. In this study, effect of garlic essential oil )0.5%, 1.5%, 2.5% w/w of film solution) on isolated soy protein films was investigated by measuring changes in properties including antimicrobial activity against (Escherichia coli H7:0157, Salmonella enteritidis and Staphylococcus aureus), mechanical (tensile strength, elongation at break), physical (transparency, water vapor permeability, microstructure) and sensory (chewing, apparent and odor). Incorporation garlic oil improved mechanical and water vapor permeability properties and decreased transparency, structure and organoleptic attributes (p

Abstract In this study, effects of Guar and Arabic gum on the viability of two common probiotic, Lactobacillus acidophilus and Bifidobacterium lactis, in frozen yogurt during 60 days were investigated. Results of survival evaluation of probiotics showed that although during storage time bacteria counts decreased significantly, this product could maintain 107 cfu/gr of probiotic at the end of storage. Maximum death rate of lactobacillus acidophilus was observed in control sample. Best viability of this microorganism was seen in samples containing 0.2% guar gum and 0.1% Arabic gum that these two treatments had no significant difference. The highest loss of bifidobacterium lactis belonged to sample containing 0.3% guar and lowest was seen in samples containing 0.1% Guar and 0.1% Arabic gum.

Abstract The objective of this work was to determine the effect of pre-frying elimination through the addition of methylcellulose and the influence of wheat flour partial replacement with corn flour (5 and 10%) on some quality factors of deep fat fried shrimp nuggets and compare the results with traditional process including pre-frying step. All batters showed shear-thinning behavior (n ≤ 0.624) and provided a good fit with power law model (R2 ≥ 0.979). Methylcellulose produced a significant increase in the consistency index of the batters. The highest pick-up value (57.68%) and the lowest oil content were found in 2% MC added batters that contained 5% corn flour, which was consistent with its high apparent viscosity. Results showed that the pre-frying elimination is an effective way in reducing oil content (%46) in deep fat fried shrimp nuggets.

Abstract The effect of addition of Qodumeh shahri (Lepidium perfoliatum) seed gum on the emulsion properties were investigated in this study. L. perfoliatum seed gum with 0-0.6% (w/w) concentration was used together with 2% (w/w) WPC to emulsify 20% (w/w) corn oil. The emulsion was analyzed for emulsion stability, particle size, specific surface area, particle size distribution and rheological properties. The mean particle size of emulsion decreased by increase in Qodume shahri seed gum up to 0.2% (w/w). Further increase in gum concentration had no significant effect on mean particle size of emulsion. Moreover, increase in gum concentration had no significant effect on particle size distribution (span) and specific surface area (m²/ml) of the emulsions. The rheological data indicated that increase in gum concentration significantly affected the viscosity, consistency coefficient (k) and flow behavior index (n) of the emulsions. Viscosity and consistency coefficient increased by increasing gum concentration. However, the flow behavior index decreased by the increase in Qodume shahri gum concentration. The flow behaviors of emulsions containing gum were well predicted by Herschel–Bulkley model (R2 > 0.99). While, in absence of gum, emulsion Showed Newtonian behavior.

Abstract The objective of this study was to evaluate the effect of frying temperature, time and different batter formulations on the rheological properties and mass transfer during deep fat frying of Kurdish cheese nuggets. The effects of white egg (0, 5, 10%) addition to the batter formulation of cheese nuggets and frying at 150, 170 and 190◦C for 0, 1, 2, 3 and 4 min have been investigated. The results showed an interaction effect of these processing conditions on mass transfer. The most reduction in fat absorption was observed when samples were coated with batter containing 10% white egg and fried at 150 ◦C. The kinetic model based on the Fick’s law was used to describe moisture transfer data. The effective moisture diffusivity of batter without white egg was within the range of 3.97×10−8 and 7.51×10−8m2/s with R2 between 0.91 and 0.86 .In the samples coated with the batter including white egg, the effective diffusivity ranged between 2.26×10−8 and 5.96×10−8m2/s with R2 between 0.98 and 0.87, and fat transfer rate constant was between 1.1×10−3 and 8.9×10−3 s−1 with R2 from 0.82 to 0.99. Activation energy obtained from the Arrhenius plot for the effective moisture diffusivity of batter with and without white egg was 30.01 kJ/mol and ranged from 38.42 to 36.52 kJ/mol, respectively

Abstract In this research effectiveness of immersing three types of contaminated pistachios fresh with hull (exocarp or epicarp), dried in shell and dried with hull from Ohady cultivar in ozonated water 0 ppm (control), 4 and 8 ppm ozone concentrations in aqueous solution for range of exposure times 0(control), 2, 4, 6, 8, 10 and12 hours, to decrease of aflatoxin (B1, B2, G1, G2 and total) were investigated. Water temperature and pH were 10°C and 5.5± 0.3 respectively. For all samples, interaction between, ozone concentration and exposure times or pistachio type, were investigated. Aflatoxin (AF) B1 content was more and was reduced easily. Results showed that differences between the control samples (zero hour and/or 0ppm ozone) and treated pistachios for total aflatoxins and aflatoxin B1 were significant(P < 0.05). For control samples, the means of aflatoxin reduction for B1, B2, G1, G2 and total were, 5.6, 9.7, 14, 6, 15 and 6.4 percentage, respectively and for ozonated pistachios were 32.7, 8.55, 30.6, 34 and 35 percentage, by 4ppm ozone concentration. The results for 8ppm ozone concentration were, 47.9, 12.5, 45.8, 43.9 and 44.4percentage, respectively. The results indicated that the effect of ozonated water on reduction of aflatoxin content from the samples significantly depends on the level of ozone concentration and exposure times. The results also demonstrated that ozone susceptibility of aflatoxins to destruction were B1 & G1 >G2 & B2 respectively.

Abstract Low-fat butter is water in oil emulsion comprising a continuous fat phase including butter, emulsifiers and colorants and also a dispersed aqueous phase including water, stabilizers and proteins. In this research, by using protein components especially full-fat soy flour, a product were produced which has extreme similarity to ordinary butter and also has good organoleptic properties. Water : butter ratio, soy flour : sodium caseinate ratio and emulsifier content were the designed factors and their effects on sensory properties of low-fat butter such as softness, spreadability, crumbling, hardness, adhesiveness, cohesiveness, melting rate, mouth coating, gumminess, butter flavor, soy flavor and finally overall acceptance were evaluated. The Central Composite Design (CCD) and Response Surface Methodology (RSM) were employed as experimental design and statistical analysis. Based on final results, the optimum formulation for low-fat butter were: water : butter ratio as 1.03 (50% water and 48.5% butter), soy flour : sodium caseinate as 1.57 (5% soy flour and 3.2% sodium caseinate) and 0.66% emulsifier. Apart from good nutritional effects of final product due to high protein content and lower fat content, that was spreadable at low temperatures and also has plastic characteristics of butter at ambient condition.

Abstract Oil uptake occurs mainly during cooling immediately after frying. Post-frying centrifuge step used to remove the attached oil to the surface of friedproduct. Response surface methodology (RSM) technique was used to develop models for the responses to the centrifugal force (100, 200 and 300 rpm) and centrifugal time (20, 50 and 80 s), frying temperature (140, 170 and 200 C) and frying time (4, 6 and 8 min), Investigated factorsoptimized with respect totheoil and moisture contents, color and textural parameters. The models showed very well fitness with experimental data. The coefficients of obtained models with RSM, was optimized by using genetical gorithms and was observedthat GA optimized models showingbetterfitnesswith theexperimentalresults than RSM models. The resultssuggest thatpost-frying centrifuge step in300 rpm for 80 sand fryingin 175-180Cfor 7-8 minleadsto French fries withlowestmoisture and oil contentand best color and texture.

Abstract Introduction: Camel carcasses has lower fat content in comparison with cow, moreover, camel meat has relatively higher polyunsaturated fatty acids and lower cholesterol contents (Kadim et al., 2009a & 2006). However, calcium amount of camel meat is greater than that of cow, and its lower consumption is partly related to this issue. With increasing demand of camel meat, more attention has been paid to the quality and chemical composition of it. Acid marinade can be used through the diffusion of the solution and its propagation over time as an extensive method to improve the meat tenderness (Yusop et al., 2010). Lactic acid is often used in the meat industry as an antimicrobial during carcass slaughter. In addition, lactic acid can improve meat tenderness (Hinkle et al., 2010). The aim of the present study was to determine the influence of lactic acid and sodium chloride on textural and sensory properties, also and proteolysis pattern of biceps femoris muscle of camel.   Materials and Methods: Six 4 to 7 years old camels were transported to the slaughterhouse in Mashhad (Iran). Slaughtering and dressing of camels were carried out according to Islamic methods. All chemicals and reagents in the experiments were of analytical grade and purchased from Merck and Sigma-Aldrich companies. Biceps femoris muscle was used as an experimental material, cutting into 2×2×5 cm3 pieces, and laid in lactic acid solutions (0, 0.5, 1, and 1.5% v/v, all accompanied with 2% w/v NaCl) at a ratio of 1 to 4 (meat  to marination solution) within plastic bags. Marination process was carried out for 0, 24, 48, 72 h at 4 °C. The meats were then removed from the marinade and dried lightly. After that, moisture, ash, protein and fat contents of the meat were specified by AOAC (2002). Shear force was measured by TA.XT plus texture analyzer (Stable Micro Systems, UK) provided with a Warner-Bratzler shear force blade method in order to evaluation of meat tenderness (Byrne et al., 2000). Myofibrillar fragmentation index (MFI) was determined as described by zahedi et al. (1393). Sarcomere length was measured with the method of Botha et al. (2007). One-dimensional gel electrophoresis was determined as described by zahedi et al. (1393). Collagen content was specified by AOAC (1993). Sensory properties including color, texture, flavor, juiciness and overall acceptance were performed using a 5-point structured hedonic scale (Hoffman et al., 2006 & 2008). One-way analysis of variance (ANOVA) was used to determine the significant differences between treatments using SPSS software (version 19). Duncan’s multiple range test was used to compare the means.   Results and discussion: Acid concentration and marination time had a significant effect (p <0.05) on sarcomere length. It was likely due to the fact that the addition of acid led to increase in pure positive charges on myofibrils and cytoskeletal proteins. As a result, more repulsive forces were generated between the protein molecules of myofibrils. Eventually, myofibrils swelling caused distancing Z lines from one another, and increasing the sarcomere length (Ke et al., 2008). The results of analysis of variance showed that the concentration of lactic acid had a significant effect on MFI (p<0.05), and MFI value was less than zero at 0% concentration, however, it was non-significant in relation to the time (p> 0.05). The higher MFI values of the marinated samples may be due to the proteolysis of myofibrile proteins using D-cathepsins which activated at acidic pH (range 3-6).  Meat samples marinated in the highest concentration for 72 h showed the lowest WBSF (p<0.05). The tenderising mechanism of acid marinades was believed to be including weakening of structures due to swelling of meat, increasing proteolysis by cathepsins, and conversion of collagen to gelatin at low pH during cooking (Berge et al., 2001; Offer & Knight, 1988). The retention time and acid concentration did not have a significant effect (p> 0.05) on the collagen amount of lactic acid treated samples. It was likely that low acid concentration, although affecting some of the parameters, is not suitable for degradation of connective tissue (Hinkle et al., 2010). Sensory analysis showed that tenderness of the samples marinated at with 1.5% acid received the highest score (p<0.05), which was consistent with the instrumental results. Acid concentration significantly affected (p<0.05) total acceptance of the samples. Higher levels of acid can be used for marinating without adversely affecting the consumer acceptance. Results from SDS-PAGE showed that number of seven bands on gels, on average, were belonged to intact proteins, and other bands were considered as peptides which resulted from proteins proteolysis, especially heavy proteins. Also, time had non-significant effect on band area of myosin heavy chain (p>0.05), while, acid concentration had a significant effect on the area of ​​this protein (p<0.05). The band area of proteins C, α-actinin and actin proteins enhanced as a function of acid concentration and marination time (p<0.05). In conclusion, we can claim that lactic acid and sodium chloride can be used as an effective acidic marination to improve biceps femoris muscle of camel meat. This method can be advice as a trick for tenderizing camel meat in household consumptions, restaurants and also meat industry, thereby increasing demand for camel meat in order to gain further healthy benefits of it.

Abstract Due to the need to find new protein sources with considering the fact that the bitter vetch seed has high levels of protein content, physicochemical and mechanical properties of bitter vetch seed and functional properties of its flour were evaluated in this study. The effects of altering the pH on protein solubility, foaming capacity, foaming stability, emulsion capacity and emulsion stability were studied. The average length, width and height of the grains were 3.5638 mm, 3.6197 mm and 3.8365 mm. the arithmetic and the geometric mean diameter, sphericity and the area were 3.6733mm, 3.6701mm, 1. 0318 and 42.405mm2 respectively. The average true density, bulk density and porosity were 1326.6 kg/m3, 0.7962 kg/m3 and 40.2753% respectively. also the average coefficients of static friction of the plywood, glass, rubber, fiberglass and galvanized iron surface layer were 0.4348, 0.1943, 0.4244, 0.3249 and 0.3739 respectively. Flour produced from this seed contains 24% protein and 9% fat. water and oil absorbing capacity were obtained 2.01 ±0.01 and 1.77±0.03 respectively (grams of water or oil per grams of sample). The results also showed that changes in pH, affected the solubility, foaming capacity, foaming stability, emulsion capacity and emulsion stability of bitter vetch flour.