Abstract: In order to evaluate the taste compounds and taste characteristics of red sufu during its fermentation process, the samples collected at different fermentation stages were analyzed by ion chromatography, amino acid analyzer, and electronic tongue. The obtained data were analyzed by principal component analysis (PCA) and hierarchical cluster analysis (HCA). Results showed that a total of 17 free amino acids (FAAs), 6 organic acids and 8 taste attributes were identified and quantified in all samples. Total contents of FAAs increased significantly at pre-fermentation and post-fermentation stages, while total contents of organic acids showed a significant increase at the pre-fermentation stage and the middle stage of post-fermentation (P < 0.05). The levels of most FAAs and organic acids increased significantly at the pre-fermentation and post-fermentation stages (P < 0.05). Electronic tongue analysis showed that umami, saltiness, bitterness and richness were major taste attributes. Furthermore, correlation analysis between taste compounds and taste attributes showed that free amino acids (Glu, Asp, Ala, Gly, His, Cys, Phe, Met and Val), organic acids (lactic acid, acetic acid, succinic acid) and some other chemical components (reducing sugar, amino acid nitrogen and NaCl) played an important role in the taste characteristics of red sufu. The results of PCA and HCA showed that the taste compounds and taste attributes could be used to evaluate its maturity extent and that electronic tongue could be a rapid tool for the taste evaluation of red sufu.

Key words: red sufu; electronic tongue; taste compounds; free amino acids; organic acids