Comprehensive explorations of nutritional, functional and potential tasty components of various types of Sufu, a Chinese fermented soybean appetizer

Abstract The nutritional, functional and tasty components of three categories of Sufu, divided by strains in the culture phase, were comprehensively investigated in this study. The levels of isoflavones, γ-aminobutyric acid (GABA), phytosterols and soyasaponin were 0.58-2.20, 7.46-57.95, 0.73-2.72 and 10.89-23.35 mg/g dry matter (DM), respectively. Glu was the most abundant of the 17 detected free amino acids (FAAs), followed by Phe, Leu, Val and Asp. Additionally, potential tasty peptide profiles were typed by the segment of molecular weight (MW) < 300 Da, ranging from 79.22% ± 4.12% to 95.24% ± 2.93%. The complex taste impression based on the electronic tongue showed that the bitterness intensity was the highest, which was followed by saltiness and the umami intensity. To some extent, different Sufu categories can be distinguished according to the electronic tongue. The results provide a theoretical basis for improving the quality control and standardization of the manufacturing process.