Optimization of Preparation Conditions and Storage Quality of Sour Cream Fermented by Lactococcus lactis grx602

Sour cream is a functional dairy product with a unique taste and high nutritional value. In this study, <i>Lactococcus lactis</i> grx602, a strain capable of degrading milk fat, was used to produce sour cream (a fermented dairy-based emulsion, designated as Lg-sour cream). The preparation process was optimized and the quality stability during storage was evaluated. The optimal preparation parameters were identified as double-pass homogenization (15.0 MPa, 70 °C), a 1% inoculation level, and fermentation at 37 °C. During storage, Lg-sour cream exhibited acceptable fluctuations in fermentation characteristics (viable cell count, pH and acidity), continuous decreases in textural properties (hardness, adhesiveness, cohesiveness, and elasticity), progressive declines in rheological properties (water-holding capacity, apparent viscosity and viscosity), and positive variations in free fatty acid composition (types and contents of fatty acids with different chain lengths). This study provides an in-depth exploration of the nutritional value, storage stability, and processing of Lg-sour cream fermented with <i>L. lactis</i> grx602, aiming to develop a novel sour cream with potential health benefits using <i>L. lactis</i> grx602 as the starter culture.