Abstract:Ultra-high temperature (UHT) instantaneous sterilization, pasteurization and infusion (INF) technology are commonly used in milk sterilization. In this study, solvent assisted flavor evaporation (SAFE) method was used to study the difference of volatile flavor components in raw milk and three kinds of sterilized milk. The results showed that there were 48 volatile compounds were detected in four kinds of milk, including 11 fatty acids, 5 ketones, 6 aldehydes, 2 sulfur compounds, 6 esters, 5 alcohols, 13 aromatic and heterocyclic compounds. On this basis, the odor activity value (OAV) of the above flavor components was further determined by combining with the threshold. There were 23 key flavor compounds with OAV greater than 1 in the four milk samples, among which hexadecanoic acid,methyl ester, 2-nonanone and hexanal contributed more to the overall flavor of milk. Partial least squares (PLS) regression was used to analyze the correlation between the key flavor components and the sensory characteristics of four kinds of milk. The results showed that the sensory characteristics of INF milk and pasteurized milk were more similar, with strong milk flavor and sweet flavor, and the corresponding compounds were 2-nonanone, 2(5H)-furanone and butyl acetate. The sensory characteristics of UHT milk were cooking flavor and strong sense, which were highly correlated with dimethyl sulfone, dimethyl sulfur, 2-ethyl-1-hexanol and 2-tridecanone. In addition, the flavor components of raw milk were relatively less.