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In this study surimi was produced from big head (Hypophtalmichthys nobilis) carp and the effects of three independent factors including microbial transglutaminase (0.5%, 0.75% and 1%), salt (0%, 1.25% and 2.5%) and temperature (35 ̊C, 40 ̊C and 45 ̊C), were examined on textural properties and color parameters of produced surimi was examined. The results showed that enzyme concentration of 0.5 % and 1.25 % of salt at 45 ̊C temperature were as optimum treatment, thereby, reducing the salt percentage from 2.5 % to 1.25 % without significant reduction in textural properties such as Hardness (resistance of food at the first bitting of the food), Cohesiveness (maintaining the strength of the food during chewing) and Springiness (ability of foos to recovery of its origin shape and size at the first biting). The increasing of the amount of enzyme also resulted in reduction of WHC, significantly (p<0.05). Moreover, when the enzyme and salt were used at low concentrations, the more whiteness and lightness of surimi gel wre produced. Simultaneous effect of salt increasing and setting temperature reduction, resulted in significant higher redness (a*) (p<0.05). Besides, the effect of enzyme alone on yellow factor (b*) was not significant, whereas the simultaneous effect of increasing in enzyme and temperature resulted higher b* factor (p<0.05). 

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Through ceating crosslink in proteins, and strengthening the protein-based food structures, MTGase can positively affect the serum holding capacity and gel firmness properties of foods. Inulin is fructose polymers with 2 to 60 degree of polymerization that linked by β (2-1) fructosyl bonds. Prebiotic and bifidogenic features of this matter have caused to use it as a functional ingredient in food products. The purpose of this study was to study the effect of the addition of MTGase and long-chain inulin on the physicochemical and sensory properties of doogh. In this study, the effect of using MTGase (0-0.3%) and long-chain inulin (0-1.5%) in 5 samples of doogh was examined on physicochemical (pH, titratable acidity, density, SNF, viscosity and phase separation) and organoleptic properties (consistency, flavor, odor, color and overall acceptability). Evaluations were performed at 24 hours and 30 days of storage. The results revealed that with increase of Transglutaminase and inulin no significant difference in pH, acidity, flavor, odor between the control sample and other treatments containing inulin and MTGase after 24 hours and 30 days was observed (P>0.05). The viscosity, SNF, density, serum phase separation, consistency and overall acceptability of samples R3 (1.5% inulin and 0.3% MTGase) and R4 (1.5% inulin and 0.1% MTGase) shown superior physicochemical and sensory properties.

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The present study was conducted to investigating the effect of Persian gum (PG) and microbial transglutaminase (MTGase) on sensorial, color and microbial characteristics of ultrafiltrated semi-fat white cheese during 60 days of cold storage. In order to produce semi-fat cheeses, PG was used at three levels of 0, 0.25, and 0.5% and MTGase enzyme at three levels of 0, 0.5 and 1 unit/g of protein. The results revealed that the treatment of cheese samples with PG and MTGase enzyme had a positive effect on the sensory and quality characteristics of the product. In general, the cheese sample containing 0.5% PG and 0.5 units of MTGase enzyme attained the highest sensorial scores. Based on panelists’ preference, during the storage time, aroma and texture scores increased while color and appearance attributes decreased. The results obtained from the analysis of color values revealed that the lightness (L*) of cheeses increased with the addition of PG and MTGase enzyme treatment and decreased with the passage of storage time. Unlike the lightness, PG and MTGase enzyme had no significant effect on a* (red-green) and b* (yellow-blue) values of the experimented cheese samples. The results obtained from the microbial evaluation showed that the addition of PG increased the viability of lactic acid bacteria (LAB), but it had no effect on the count of mold and yeasts. On the other hand, increasing the concentration of the enzyme decreased the growth and survival of the studied microorganisms. The results of this study showed that PG can be used as a fat substitute along with MTGase enzyme to produce ultrafiltrated low-fat white cheese with favorable technological and sensory characteristics comparable to high-fat cheese varieties, and the best sample of ultrafiltrated semi-fat cheese is obtained using a treatment containing 0.5% PG and 0.5 unit of MTGase enzyme.