Sensory-directed characterization of key odor-active compounds in fermented milk

The present study aimed to investigate the key odor-active compounds in fermented milk by sensory-directed analysis. Sensory evaluation demonstrated that the overall odor attributes of fermented milk samples were mainly milky, sweet, sour, and buttery. A total of 35 odor compounds were detected in fermented milk samples by dynamic headspace sampling (DHS) combined with gas chromatography-mass spectrometry analysis (GC-MS). Of them, 21 odor-active compounds were detected by GC-MS in combination with olfactometry (O). In addition, 10 key odor-active compounds were screened by DHDA (flavor dilution (FD) factors, FD >= 27), odor activity value (OAV) calculation (OAV >= 1) and recombination experiments, including 2,3-butanedione, 2,3pentanedione, 2-heptanone, 2-undecanone, acetic acid, butanoic acid, hexanoic acid, hexanal, nonanal, and 2pentylfuran. This study provides a basis for subsequent flavor studies of fermented milk and provides theoretical guidance for quality control of fermented milk.