Analysis of Volatile Aroma Components of Navel Orange Wine Produced by Mixed Fermentation of Non Saccharomyces cerevisiae and Saccharomyces cerevisiae Based on GC-IMS

To investigate the aroma-enhancing effect of different non-Saccharomyces cerevisiae on mixed fermentation of navel orange wine, the volatile aroma components of mixed fermentation of navel orange wine with different yeasts were determined by gas phase ion transfer spectroscopy (GC-IMS). The results showed that 49 volatile compounds were identified in navel orange wine. Torulaspora delbrueckii PL09+Saccharomyces cerevisiae DV10 fermentation wine contained high contents of 3-methyl-1-butanol, 4-methyl-1-pentanol, 1-penten-3-one and ethyl isobutyrate, with prominent aromas of apple, citrus and mulberry fruit. Hanseniaspora JW14+Saccharomyces cerevisiae DV10 and Hanseniaspora DY5+Saccharomyces cerevisiae DV10 fermented wines had high contents of aldehydes, ketones, and esters such as 3-hydroxy-2-butanone, 4-methyl-2-pentanone, butyraldehyde, ethyl acetate, and ethyl propionate, with aromas of cream, pineapple, and other fruit flavours. The mixed bacterial fermentation was able to add new volatile aroma components that were not present in the monobacterial fermentation. 3-hydroxy-2-butanone, octanol, 1-penten-3-ol, and 4-methylpentan-2-one were the unique aroma components in samples Hanseniaspora JW14+Saccharomyces cerevisiae DV10 and Hanseniaspora DY5+Saccharomyces cerevisiae DV10. 3-methyl butyraldehyde was the unique aroma component in sample Torulaspora delbrueckii PL09+Saccharomyces cerevisiae DV10. PCA analysis showed that Hanseniaspora DY5+Saccharomyces cerevisiae DV10 differed less from Hanseniaspora JW14+Saccharomyces cerevisiae DV10, both of them differed from Torulaspora delbrueckii PL09+Saccharomyces cerevisiae DV10 and all significantly differed from Saccharomyces cerevisiae DV10 monoculture fermentation, demonstrating that non-Saccharomyces cerevisiae could contribute to aroma enhancement and that there were differences in the aroma enhancement effect between their species. Sensory evaluation showed that Hanseniaspora JW14+Saccharomyces cerevisiae DV10 had the highest score. To sum up, the addition of non-Saccharomyces cerevisiae to ferment navel orange wine could effectively enhance the flavor characteristics of navel orange wine. Hanseniaspora JW14+Saccharomyces cerevisiae DV10 fermented navel orange wine was better overall, and the flavor was more complex. This study could provide reference for the future fermentation of navel orange wine with non-Saccharomyces cerevisiae and Saccharomyces cerevisiae.