Characterization of Flavor Properties of Sufu by HS-SPME/GC-MS, Electronic Nose and Electronic Tongue Combined with Multivariate Statistical Analysis

Flavor is the main quality characteristic of sufu. The flavor of different types of sufu varies greatly, which will affect the preference and selectivity of consumer for sufu. To explore the flavor characteristics and distinguishing methods in different types of sufu, the volatile flavor components and free amino acids of 5 kinds of commercial sufu were determined by HS-SPME/GC-MS and amino acid automatic analyzer, respectively. Moreover, the electronic nose and electronic tongue were used to distinguish the sufu samples. The results showed that a total of 71 volatile aroma compounds were identified, in which esters (28.43-79.17%) were the main flavor substances. The total free amino acid contents in different types of sufu were at a range of 24.8-33.89 mg/g. Bitter amino acids were dominant in all sufu (except GS). PCA of electronic nose and electronic tongue showed that the electronic nose can only distinguish the grey sufu, while the electronic tongue can effectively distinguish among types of sufu. PLS-DA based on aroma and taste substances showed that sufu can be distinguished. According to VIP, fifteen volatile flavor components and five taste amino acids could be used as the main different compounds of sufu. The research results pretended that HS-SPME/GC-MS, electronic tongue technology combined with multivariate statistical analysis method can effectively distinguish sufu. These findings will provide guiding significance to identify the types of sufu and consumers’ purchase products and promote the development of sufu industry to a certain extent.