HS-GC-IMS with PCA to analyze volatile flavor compounds across different production stages of fermented soybean whey tofu

Abstract

The variations in flavor substances across the different stages of fermented soybean whey tofu (FSWT) production were analyzed by headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) combined with principal component analysis (PCA). The results revealed 24 representative flavor compounds in the samples across all production stages. After heating, the signal intensity of hexanal, 1-octen-3-ol, heptanal, and (E)-2-hexenol, which are unpleasant flavor substances found in raw soymilk, weakened, whereas those of some aroma substances increased. Furthermore, fermented flavor compounds, namely, 2-heptanone, 2-pentylfuran, pentanal, and 2,3-butanedione, were produced after the addition of fermented soybean whey as a coagulant. A PCA based on the signal intensity of the detected volatile compounds revealed effective differentiation of samples from different stages into comparatively independent spaces. These results showed that the flavor fingerprints of the samples from different stages of FSWT production can be successfully built using HS-GC-IMS and PCA based on the detected volatile compounds.

Keywords: (E)-2-Hexenol (PubChem CID5318042); 1-Hexanol (PubChem CID8103); 1-Octen-3-ol (PubChem CID18827); 2,3-Butanedione (PubChem CID650); 2-Heptanone (PubChem CID8051); 2-Pentylfuran (PubChem CID19602); Benzaldehyde (PubChem CID240); Fermented soybean whey tofu; Flavor fingerprint; Headspace-gas chromatography-ion mobility spectrometry; Heptanal (PubChem CID8130); Hexanal (PubChem CID6184); Pentanal (PubChem CID8063); Principal component analysis; Volatile profile.