Comparison of potent odorants in high-salt liquid-state fermentation soy sauce before and after sterilization

Abstract

To compare the changes of potent odorants (PO) in high-salt liquid-state fermentation soy sauce (HLFSS) after sterilization under 120°C for 15 s, the volatiles in HLFSS were isolated by solvent extraction combined with solvent-assisted flavour evaporation and were analysed by gas chromatography-mass spectrometry-olfactometry. A total of 40 odour-active compounds were identified, and their flavour dilution (FD) factors ranging from 1 to 4096 were determined by comparative aroma extract dilution analysis. Twenty-four compounds with FD factors ≥8 were quantitated by establishing standard curves, and the results showed that total concentrations of alcohols and phenols were almost unchanged, those of esters, acids and pyrazines decreased and those of aldehydes and ketones increased. Based on quantitative results and thresholds in water, odour activity values (OAVs) were calculated. Eighteen compounds with OAVs ≥1 were determined as PO in HLFSS. The number of POs did not change after sterilization, and OAVs of 10 POs remained unchanged or varied very little. The significant changes in the concentrations of methional, 5-ethyl-4-hydroxy-2-methyl-3(2H)-furanone, nonanal, ethyl 2-methylbutanoate, methionol, benzeneacetaldehyde, 4-hydroxy-2,5-dimethyl-3(2H)-furanone and 2-ethyl-3,5-dimethylpyrazine after sterilization caused the obvious variations of OAVs, which made cooked potato, caramel-like, fatty and floral notes in HLFSS change in different degrees. The results obtained have some reference value to produce SS.