Journal of Food Processing & Technology

Influence of enzymatic modification through microbial transglutaminase on properties of probiotic yoghurt

International Conference and Exhibition on Food Processing & Technology

November 22-24, 2012 Hyderabad International Convention Centre, India

Saina Moayedzadeh, Khosrowshahi Asl, Zomorodi SH

Accepted Abstracts: J Food Process Technol

Abstract:

The effect of microbial transglutaminase concentration, amount of sodium caseinate and storage time on Lactobacillus casei viability in nonfat stirred yoghurt and it`s physical and sensory properties was investigated using response surface method (RSM). Enzyme concentration, amount of sodium caseinate and storage time were in the range of 0-2 Unit per gram of milk protein, 0-1.27 percent and 1-19 days, respectively. The statistical analysis of the results showed that by increasing enzyme concentration, Lactobacillus casei viability increased significantly and syneresis decreased (p≤0.05). With respect to sensory evaluation results, as the amount of sodium caseinate increased, color score decreased significantly and by increasing transglutaminase concentration, flavor score was raised. As the enzyme concentration and amount of sodium caseinate increased, overall acceptability of the samples also increased significantly (p≤0.05). Based on the empirical models obtained by response surface methodology a proper relationship was detected between the study variables. According to the results, the optimum conditions for the production of yoghurt was obtained using 1.41 Unit enzyme per gram of milk protein, 0.31 percent sodium caseinate with a storage period of 15 days. Under these conditions the predicted Lactobacillus casei counts was 8.33 logarithmic cycle, the percentage of syneresis was 6.72 and color and overall acceptability rate were 3.37 and 3.87 out of 5, respectively.