Abstract:
Objective:To investigate the influences of different cultivars and fermentation periods on the volatile components of kiwifruit wines. Methods:The head space solid phase micro-extraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) technology were used to analyze the volatile aroma components of three kiwifruit wines fermented from "Jinyan" kiwifruit, "Hongyang" kiwifruit and "Miliang 1 hao" kiwifruit. Results:During the whole fermentation process, the main aroma components of these kiwifruit wines included 17 esters, 5 alcohols and 2 acids. Four principal components were screened through the principal component analysis in terms of these 24 aroma components detected. The first principal component involved almost all esters, which presented flower and fruit fragrances. The flower and fruit fragrances of "Hongyang" and "Miliang 1 hao" kiwi wines formed within 12 d, and this fragrances of "Jinyan" Kiwifruit wine formed within 5 d, thereafter the fragrances gradually weakened. The esters total content of "Jinyan" Kiwifruit wine was higher than that of the other two kiwifruit wines during the whole fermentation process. About the second principal component, phenethyl alcohol was the most important aroma, which reflected the rose fragrance. The contents of phenethyl alcohol from "Hongyang", "Jinyan" and "Miliang 1 hao" kiwifruit wines reached the most value on the 5th, 19th and 12th day, respectively. The content of phenethyl alcohol from "Miliang 1 hao" was higher than that of the other two kiwifruit wines, so that "Miliang 1 hao" kiwifruit wine showed outstanding rose fragrances. The third principal component included isobutyl alcohol and isoamyl alcohol, which reflected the main higher alcohols of fruit wine. The contents of higher alcohols increased to the maximum after fermentation for 5 d, following with a decrease trend. The contents of higher alcohols from "Miliang 1 hao" and "Hongyang" kiwifruit wines were significantly higher than that of "Jinyan" kiwifruit wine. The fourth principal component was ethanol, and the ethanol contents of these three kiwifruit wines reached the most values after 5 days fermentation, then it slightly decreased on the 12th day, finally it returned to the before on the 19th day. Conclusions:The main fragrance of kiwifruit wine was formed during the pre-fermentation process, and the contents of most aroma components decreased then tended to be stable during the post-fermentation process. The esters contents of "Jinyan" kiwi wine were higher than that of the other two kiwifruit wines, with more abvious floral and fruity aromas and the phenethyl alcohol content of "Miliang 1 hao" kiwifruit wine was higher than that of the other two kiwifruit wines with more rose fragrance.