Investigation of the viability of probiotic bacteria, sensory characteristics and proteolysis in probiotic soy cheese during storage

Probiotic soy cheese is a fermented soy milk product that has nutritional and health properties. The aim of this study was to investigate the effect of kind of probiotic culture on the sensory properties and proteolysis in soy probiotic cheese during storage. Probiotic soy cheese was produced using cheese starter (25% thermophilic + 75% mesophilic) as well as probiotic strains of Lactobacillus acidophilus, L. casei and Bifidobacterium lactis. The control sample (without probiotic bacteria) was also produced. These samples were stored for 1 month. Probiotic bacteria added to soy cheese had good survival, therefore after one month storage, the probiotic bacterial count was more than 7 log CFU/g. The quantity of soluble nitrogen and non-protein nitrogen in the samples increased during storage. Treatment 3 (containing cheese starter + B. lactis) had a higher rate of proteolysis during storage than the other treatments. Taste, odor, texture and overall acceptance scores of sampels decreased during storage (p<0.05) but no change in color score was observed.  Treatment 1 (containing cheese starter + L. acidophilus) obtained the highest score of sensory overall acceptability and was recognized as the superior treatment.