Characterization of key odor-active compounds in thermal reaction beef flavoring by SGC×GC-O-MS, AEDA, DHDA, OAV and quantitative measurements

Thermal reaction beef flavoring is a kind of food additive. In this study, three extraction methods of dynamic headspace sampling (DHS), solid phase micro-extraction (SPME) and liquid-liquid extraction (LLE) combined with switchable two-dimensional gas chromatography-olfactometry-mass spectrometry (SGC×GC-O-MS) were employed to characterize volatile compounds in thermal reaction beef flavoring. The odor characteristics of thermal reaction beef flavors were identified by sensory evaluation, aroma extraction dilution analysis (AEDA), dynamic headspace dilution analysis (DHDA), odor activity value (OAV) and quantitative measurements. A total of 231 volatile odor compounds were identified by the three extraction methods, which including 15 aldehydes, 41 ketones, 29 alcohols, 27 esters, 13 furans, 20 pyrazines, 9 sulfur-containing compounds, 18 thiophenes and thiazoles, 19 acids and 40 other compounds. Ninety-eight compounds had odor activity, and 22 odor-active compounds were quantitatively analyzed. 2-Methyl-3-furanthiol (meaty) and bis(2-methyl-3-furanyl) disulfide (onion) had the higher FD and OAV, 3-methylbutanal (chocolate) was first identified as the key odor-active compound in thermal reaction beef flavoring, methyl furfuryl disulfide (meaty), 2-ethyl-3,5-dimethylpyrazine (roasted nuts), 2,3-butanedione (caramel), linalool (floral), furfural (baked bread), 2-furfurylthiol (sulfury) and other compounds were also identified as the key aroma components in thermal reaction beef flavoring. The results showed that SPME and DHS were more suitable than LLE for the separation and extraction of volatile odor compounds in thermal reaction beef flavoring, and there were some masking and synergistic effects between odor-active compounds.