Analysis of Changes of Volatile Aroma Compounds in Asparagus-Kiwifruit Wine during Fermentation

Asparagus-kiwifruit wine was prepared by mixed fermentation of squeezed asparagus byproducts and kiwifruit juice. The volatile aroma components of asparagus-kiwifruit wine in the early, middle, late, post-fermentation and aging stages were analyzed by solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS). A total of 78 volatile aroma components were detected during the whole fermentation stage, and the most volatile aroma components in each fermentation stage were esters and alcohols. Among them, ethyl ester accounted for a relatively large proportion of the total ester, which was 54.72%, 79.20%, 72.92%, 76.60% and 70.14%, respectively. As the fermentation progressed, the types of volatile aroma substances gradually decreased and tended to stabilize, and the mass concentration first increased and then decreased and stabilized. Isoamyl acetate, ethyl caproate, methyl phenylacetate, ethyl octanoate, ethyl phenylacetate, ethyl decanoate, isoamyl alcohol, isobutanol, phenylethanol and 2,4-di-tert-butylphenol were common volatile aroma substances in the whole fermentation stage. 13 kinds of characteristic aroma substances were obtained by the method of odor activity value (OAV), and ethyl caproate and ethyl octanoate were the characteristic aroma substances shared in the whole fermentation stage, among which ethyl octanoate was the compound with the largest OAV value in each fermentation stage. The main characteristic aroma substances in the early stage of fermentation were ethyl octanoate and phenylacetaldehyde. The main characteristic aroma substances in the middle and late fermentation were ethyl octanoate and ethyl caproate. The main characteristic aroma substances during post fermentation and aging were ethyl octanoate and 2-methyl butyl acetate. This study analyzed the characteristic flavor of asparagus-kiwifruit wine, and provided a theoretical reference for the development of asparagus-kiwifruit wine.