Dynamics of flavor compounds and microbial communities in sour cream with different fat contents

Milk fat is an important nutritional component in sour cream and contributes to its unique flavor. This study investigated the dynamic changes in flavor compounds and microbial communities of sour cream with different fat content. The results showed that fat content is a key factor affecting the flavor of sour cream. A total of 19 key aroma compounds were identified by GC–MS, including esters, methyl ketones, aliphatic aldehydes, lactones, and sulfur compounds. These substances are mainly derived from esterification, amino acid metabolism, and β-oxidation of fatty acids. Additionally, Lactococcus was the dominant microorganism in sour cream and was closely associated with the formation of various flavor compounds. Notably, the F20 group (20% fat) exhibited superior sensory properties and flavor characteristics. These findings lay a theoretical foundation for optimizing sour cream quality and enhancing flavor.