Effect of enzymatic hydrolysis on volatile flavor compounds of Monascus-fermented tartary buckwheat based on headspace gas chromatography-ion mobility spectrometry

Tartary buckwheat was hydrolyzed with α-amylase, pullulanase, α-amylase and pullulanase double enzymes and fermented by Monascus. The fermentation products were named as enzymolysis-Monascus-fermented tartary buckwheat (EMFTB). The composition and content of volatile flavor compounds in EMFTB were investigated. The results showed that α-amylase and pullulanase hydrolysis reduced starch content and raised protein, flavonoids, Monacolin K and Monascus pigments content of EMFTB. Meanwhile, double enzyme hydrolysis significantly changed the principal components of volatile substances and affected the varieties and content of volatile organic substances in EMFTB using electronic nose and headspace gas chromatography-ion mobility chromatography (HS-GC-IMS). The volatile organic substances and main aroma components increased significantly in EMFTB, including 2-heptanone, 3-methyl-1-butanol, butan-1-ol, 2-methyl-1-propanol and other substances. These results indicate that the amylase hydrolysis plays an important role in improving the flavor quality of EMFTB.