Characterization of potent odorants in northern Thai fermented black and yellow soybeans (thua nao) using solvent-assisted flavor evaporation, aroma extract dilution analysis techniques and omission studies of aroma reconstit

Abstract

In this study, potent odorants in thua nao made from black (BSB) and yellow (YSB) soybean were characterized using solvent-assisted flavor evaporation (SAFE) coupled with gas chromatography-mass spectrometry (GC-MS). The volatile compound content was quite similar between the BSB and YSB samples. In addition, aroma extract dilution analysis (AEDA) coupled with gas chromatography-olfactometry (GC-O) and odor activity value (OAV) techniques were used to tentatively identify potent aroma compounds with flavor dilution (FD) factors >= 27 and OAVs >= 1. Based on aroma attributes, thirty aroma-active compounds were classified into nine groups, with four of these omitted odorant groups (sour/fermented, smoky/woody, nutty, and fatty/oily) showing a significant contribution to the overall aroma of thua nao products, as confirmed by aroma recombination and omission experiments. This research provided valuable information for understanding the composition of key aroma compounds in thua nao products.