Effects of Yeast Fermentation with Different Varieties on Flavor Compounds of Bean Sauce Based on GC-IMS Combined With Multivariate Statistical Methods

To investigate the effects of Angel yeast, Meyerozyma guilliermondii, Saccharomyces cerevisiae, Zygosaccharomyces rouxii and Candida parapsilosis fermentation on volatile flavour compounds in bean paste, the volatile flavour substances of fermented bean soup paste were analyzed by gas chromatography-ion mobility spectrometry (GC-IMS) technique using unfermented bean soup paste as a control group. The relative odour activity value (ROAV) method was used to determine the key flavour components. Principal component analysis (PCA) and partial least squares-discrimination analysis (PLS-DA) were used to comprehensively evaluate the aroma of fermented bean soup paste. A total of 50 volatile compounds were identified, which were primarily esters and alcohols in six fermented bean sauces. These compounds contribute to the distinct mellow, fruity, and malty flavour profiles characteristic of these sauces. The types and concentrations of volatile compounds in different fermented bean sauces exhibited statistically significant differences (P<0.05). Importantly, soybean sauce fermented by Saccharomyces cerevisiae demonstrated the highest concentration and diversity of volatile compounds. According to the relative odour activity value (ROAV), there were 8, 13, 9, 11, 19 and 7 key flavour substances in fermented bean sauce and unfermented bean sauce samples of Angel yeast, Pichia pastoris, Saccharomyces cerevisiae, Saccharomyces rouxeri and Candida parapsilosis, respectively. By employing PCA and PLS-DA analysis on these pivotal flavour compounds, a distinct differentiation was observed among soybean sauces fermented by various yeast strains. Moreover, a notable disparity in overall aroma between fermented and unfermented soybean sauce was identified, which substantiated the findings obtained from GC-IMS fingerprinting. The utilization of yeast fermentation in soybean sauce production holds the potential to enhance its aroma components, thereby providing a theoretical foundation for further advancements in soybean sauce processing.