Abstract: Purpose: To understand the taste and flavor characteristics of laboratory-made (M1 and M2) and commercial (C1 and C2) fermented bean curds. Methods: An electronic tongue, an automatic amino acid analyzer and solid-phase microextraction combined with gas chromatography-mass spectrometry (SPME-GC-MS) were used to analyze quantitatively and qualitatively the flavor and chemical composition of fermented bean curd. Results: Electronic tongue analysis showed that the taste of M1 was similar to that of C1 and C2, while the bitterness and sourness of M2 were higher. Amino acid analysis showed that glutamic acid contributed most to the taste of the four fermented bean curds, and the content of bitter amino acids in M2 was the highest among these. Meanwhile, a total of 73 volatile compounds were detected by SPME-GC-MS, and the relative contents of terpenes and aromatic compounds in M1 and M2 were higher, while the relative contents of ethanol in C1 and C2 were higher. Conclusions: The results from this study provide a theoretical basis for research on fermented bean curd and its production, and combined use of the above three methods can provide complementary and reliable information.

Key words: fermented bean curd, electronic tongue, amino acid analysis, solid-phase microextraction, gas chromatography-mass spectrometry