摘要

Yoghurts were fermented using different starter cultures (187, 495, or 885) for examination of the influence of soy protein hydrolysates (SPHs) on the fermentation pH and whey precipitation, as well as rheological and textural properties of the fermented products during storage. SPHs had a definite effect on the stimulation of fermentation of the three yoghurts, especially on those fermented by cultures 187 and 495 that had a lower pH reduction rate during fermentation. In storage, SPHs could effectively slow whey precipitation in the three yoghurts, where the most significant effect (reduction rate: 49.35%) was found in the yoghurt fermented by culture 885, which had the highest whey precipitation rate among the three control groups. Moreover, SPHs could greatly increase the apparent viscosity and hysteresis area of the three yoghurt samples, contributing to their structure recovery. Through further investigation of the yoghurts on the 7th day of storage, the SPH was found to have significantly improved the consistency and zero-shear viscosity of the three yoghurts, and reduced their flow behavior index, compliance value, and viscous index, thus improving their rheological and textural properties, increasing their stability under low stress, and reducing the degree of damage caused by deformation under high stress.