Analysis of Volatile Aroma Compounds in Kiwi Wine Co-Fermentation with Different Yeasts by SPME-GC-MS Combined with Electronic Nose

The effects of mixed fermentation with three different non-Saccharomy cescerevisiae strains (Torulaspora delbrueckii, Kluyveromyces thermotolerans, Pichia fermentans) and Saccharomyces cerevisiae on volatile components were investigated by combining use of solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS), electronic nose (E-nose) and sensory evaluation. The results showed that non-Saccharomyces cerevisiae single fermentation and its mixed fermentation with S. cerevisiae increased the number of volatile aroma compounds in kiwi wine compared with S. cerevisiae single fermentation. The contents of phenyl ethyls and acetate were relatively high in the co-fermentation wine with T. delbrueckii and S. cerevisiae, which improved the sensory profiles of floral and fruit aroma. The contents of higher alcohols and C₆ compounds were significantly increased by co-fermentation of K. thermotolerans and S. cerevisiae, which enhanced fruit flavor of kiwi wine. The contents of short chain fatty acids ethyl esters, terpenes and furans in kiwi wine fermented with P. fermentans were high, which increased fruit, fat and floral aroma characteristics. Therefore, mixed fermentation of different strains enhanced kiwi wine quality of volatile aroma and had different effects on aroma characteristics. In addition, GC-MS and E-nose technology combined with principal component analysis were successfully applied to distinguish kiwi wines of co-fermentation with different yeasts. Partial least squares analysis showed that E-nose could predict volatile components of kiwi wine, especially esters. This study provided a theoretical basis for the application of non-Saccharomyces cerevisiae in fruit wine, the improvement of volatile aroma in kiwi wine and multivariate analysis.