Modeling and Optimization of Physicochemical and Organoleptical Properties and Lactobacillus acidophilus Viability in ltrafiltrated Synbiotic Cheese, Containing Microbial Transglutaminase Enzyme, Whey and Inulin

The growing demand of consumers for healthy foods has created a great incentive for the advancement of new food products around the world. Functional foods, particularly synbiotic products, are one of these products. In this research, the effects of microbial transglutaminase enzyme (MTG, 0-1 units per gram of milk protein), demineralized whey powder (DWP) solution containing 34% DWP (0-16%) and inulin (0-2%) on the physicochemical, sensorial and microbial properties of Iranian white ultrafiltrated symbiotic cheese was investigated using the response surface method (RSM). For cheese production, Lactobacillus acidophilus LA5 was used as probiotic and inulin and DWP solution were used as prebiotics. The results showed that by increasing of MTG concentration, moisture content of cheeses increased significantly (P<0.05), but acidity and other physicochemical properties and sensory attributes did not change noticeably. By increasing DWP substitution with ultrafiltrate, fat and protein values (P<0.01) and all the sensory attributes (P<0.05) significantly decreased but acidity did not change remarkably. Furthermore, with increasing inulin, acidity, color and appearance, odor and flavor (P<0.05) increased and moisture content (P<0.01) decreased significantly. By increasing of MTG concentration, the number of probiotic bacteria reduced significantly but addition of DWP solution (P<0.05) and inulin (P>0.05) had adverse effect and enhanced it. The optimization results showed that by using 0.43 U/g protein of MTG, 8.24% DWP solution and 0.71% of inulin, an Iranian white symbiotic ultrafiltrated cheese with appropriate physicochemical and sensory properties could be produced. The optimized cheese had adequate total acceptability (7.76 score) and high probiotic count (6.96 logcfu/g).