Abstract:
In order to explore the effects of extrusion processing on characteristic flavor compounds of pea flour and improve the flavor quality, in this study, electronic nose(E-nose) and gas chromatography-ion mobility spectrometry(GC-IMS) were used to investigate the effects of extrusion temperatures (120, 150, 180 ℃) on volatile flavor compounds of pea flour and compared with unextruded pea flour. The flavor differences between samples with different extrusion temperatures can be evaluated objectively by the electronic nose system. A total of 53 volatile substances in 8 compounds, including aldehydes, alcohols, ketones, acids, esters, pyrazines, furans and ethers were identified by GC-IMS. The relative content of alcohols, ketones, acids, esters, ethers decreased, the relative content of pyrazines and furans increased. The relative content of characteristic beany flavor compounds such as trans-2-octenal, hexanal, 1-octene-3 alcohol, n-hexanol, 1-pentanol, n-butanol and 2-pentylfuran decreased by 23.53%, 33.23%, 50.44%, 88.82%, 77.69%, 84.51%, 26.19%, respectively and the relative content of 2, 5-dimethylpyrazine, 2-methylpyrazine and 2-furanmethanol with roasted flavor increased by 16.16, 23.92, and 7.95 times, respectively at the extrusion temperature of 180 ℃. Relative odor activity value (ROAV) showed that n-nonanal, 3-methylbutanal, hexanal, n-octanal, 1-octen-3-ol, heptanal, ethyl acetate, n-butyraldehyde, trans-2-octenal, 2-pentylfuran, 2-ethylfuran and n-hexanol were the characteristic flavor compounds of raw pea flour. Principal component score determined that the flavor of the 180 ℃ extruded sample was the best.