Flavor differences between commercial and traditional soybean paste

Abstract

Fermented soybean paste is becoming popular worldwide due to its umami taste and characteristic aroma. To elucidate the relationships between the odorants and the flavor differences of commercial soybean paste (CSP) and traditional soybean paste (TSP), 49 samples (13 CSP, 36 TSP) were collected and evaluated in this research. The aroma-active compounds of CSP and TSP samples were analyzed by electronic nose, gas chromatography-olfactometry-mass spectrometry combined with aroma extract dilution analysis, and the key aroma compounds were identified by calculation of the detection rates and odor activity values. Following characterization, 23 and 19 odorants were identified as key aroma compounds contributing to flavor differences in CSP and TSP samples, respectively. Significant differences were observed for the acids, alcohols, aldehydes, terpenes, and sulfur-containing compounds. The results showed that the flavor differences of the samples were more resulted from the concentrations of the key aroma compounds rather than their compositions and those differences mainly came from the long maturation period of TSP samples and heating process of CSP samples. Further, orthogonal partial least squares discrimination analysis revealed that the key aroma compounds identified in this research could explain the flavor differences of commercial and traditional soybean pastes.