Elucidation of key aroma-active compounds and sensory profiles in raw and thermally sterilized milks: Perspective from molecular sensory science

Thermal sterilization significantly influences milk aroma, which is a key factor affecting consumer acceptability. This study employed molecular sensory science to characterize aroma profiles and key aroma-active compounds (AACs) of raw and four thermally sterilized milks. High-intensity sterilization enhanced the milky, fatty, and sweet attributes. Eighty volatiles were identified using a self-built milk flavor database, and 45 odorants were sniffed with flavor dilution (FD) factors of 1–64. Twenty-six odorants (FD ≥ 8) were quantified using external standard calibration. To further improve the precision of quantification, eight AACs (FD ≥ 64; odor activity values ≥1) were quantified by stable isotope dilution analysis for the first time. Recombination and omission experiments revealed 16 key AACs, of which 1-octen-3-ol and butyric acid represented key contributors across five milks, octanal, nonanal, γ-nonalactone, and 2( 5H )-furanone were key contributors in the sterilized milks. These findings provide a scientific basis for optimizing milk sterilization processes.