Investigating the effects of sterilization temperatures on odor of high-temperature short-time pasteurized milk using molecular sensory science technique

The impact of changes in sterilization temperature on trace odor-active compounds during thermal treatment processes should not be overlooked. In this study, molecular sensory science technologies including sensory evaluation, comprehensive two-dimensional gas chromatography-olfactometry-mass spectrometry (GC × GC-O-MS), dynamic headspace dilution analysis (DHDA), odor activity value (OAV), aroma recombination, and omission experiments were employed to identify and characterize key odor-active compounds in various high-temperature short-time pasteurized milk (HTST) samples. The results showed that milky, fatty, sweet, fruity, fresh, and stinky were the dominant odor attributes in HTST. Ten key odor-active compounds that most significantly contributed to the overall odor profile of HTST were octanal, hexanal, decanal, 2,3-butanedione, butanoic acid, 1-octen-3-ol, 3-methylbutanal, ethyl 2-methylbutyrate, acetoin, and nonanal. With increasing sterilization temperature, the concentration of butanoic acid gradually decreased, while that of 2,3-butanedione and acetoin increased. This study provides a foundation for optimizing HTST milk production based on the influence of sterilization temperature on flavor.