Sensory-Directed Characterization of Key Odor-Active Compounds in Fermented Milk

Abstract

The present study aimed to investigate the key odor-active compounds in fermented milks 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 with were screened by DHDA (flavor dilution (FD) factors, FD ≥ 27), odor activity value (OAV) calculation (OAV ≥ 1) and recombination experiments, including 2,3-butanedione, 2,3-pentanedione, 2-heptanone, 2-pentylfuran, butanoic acid, hexanal, hexanoic acid, 2-undecanone, nonanal, and acetic acid. This study provides a basis for subsequent flavor studies of fermented milk and provides theoretical guidance for quality control of fermented milk.

Keywords: fermented milk, odor-active compounds, dynamic headspace sampling (DHS), dynamic headspace dilution analysis (DHDA), GC-O-MS, odor activity value (OAV), odor recombination