Soybean peptides promote yoghurt fermentation and quality.

OBJECTIVES: This research paper was to investigate the influence of soybean peptides addition on viable count of lactic acid bacteria, physicochemical parameters, flavor, and sensory evaluation of yoghurt. RESULTS: The number of fermenting strains (Streptococcus thermophilus + Lactobacillus delbrueckii subsp. bulgaricus) cells in yoghurt (stored at 4 °C for 19 days) added with 0.2% (w/v) of soybean peptides (808.34 Da) reached 1.4 times higher bacterial number than in the control group. A total of 34 volatile substances were detected in this study, while there were 22 volatiles occurred in the control group yoghurt, 30 volatiles were detected in yoghurt added with 0.2% soybean peptides. There was no significant difference in sensory evaluation (p > 0.05) between the yoghurt with and without soybean peptides. CONCLUSIONS: In our study, the addition of soybean peptides (0.2%) can be effective both in maintaining the viable bacterial count and yoghurt quality.