Evaluation of Four Indigenous Non-Saccharomyces Yeasts Isolated from the Shangri-La Wine Region (China) for Their Fermentation Performances and Aroma Compositions in Synthetic Grape Juice Fermentation.

Yue Zhao,Yifan Zhu,Qingyang Sun,Bin Tian,Fei Du,Ruzhi Mao,Shusheng Zhu,Lijing Liu,Su Li

doi:10.3390/jof8020146

Abstract

This study investigated the fermentation performances and aroma compositions of synthetic grape juice that was fermented by four indigenous non-Saccharomyces yeast isolates that were obtained from the Shangri-La wine region (China): Meyerozyma guilliermondii (AD-58), Saccharomycopsis vini (BZL-28), Saturnispora diversa (BZL-11), and Wickerhamomyces anomalus (DR-110), in comparison to those of Saccharomyces cerevisiae (EC1118). The four indigenous non-Saccharomyces yeasts showed a lower fermentative capacity and a lower conversion rate of sugar to alcohol, but a higher yield of volatile acidity. W. anomalus (DR-110) had a greater ability to produce numerous esters and short-chain fatty acids and the representative flavors of its fermented medium were fruity and fatty. Sac. vini (BZL-28), interestingly, exhibited great capacity in the formation of many monoterpenes, particularly (Z)-β-ocimene, E-β-ocimene, linalool, citral, and geraniol and its fermented medium was characterized by a strong fruity (citrus-like) and floral flavor. M. guilliermondii (AD-58) and Sat. diversa (BZL-11) only mildly affected the aroma profiles of their resultant fermented media, since the concentrations of most of the volatiles that were produced by these two isolates were much lower than their sensory thresholds. The four indigenous non-Saccharomyces yeasts exhibited distinctive fermentation performances and aroma production behaviors. In particularly, W. anomalus (DR-110) and Sac. vini (BZL-28) have shown good potential in enhancing the aromas and complexity of wine.

Highlights

Wine fermentation is a complex biochemical process that is conducted by many different microorganisms
Non-Saccharomyces yeasts were usually isolated from sour wine and associated with unpleasant flavor, oenologists tend to inhibit the activity of these yeasts during wine fermentation [2]
Some non-Saccharomyces yeasts like Lachancea thermotolerans, Pichia kudriavzevii, and Schizosaccharomyces pombe have shown potential in regulating acidity during wine fermentation, which could be used for improving the quality of must containing excessive or insufficient acidity [5,6,7]

Summary

Introduction

Wine fermentation is a complex biochemical process that is conducted by many different microorganisms. S. cerevisiae yeasts are more favored in wine production for their reliable fermentation characteristics with consistent quality [2]. Hanseniaspora, Metschnikowia, Starmerella, and Zygosaccharomyces have shown a lower sugar–ethanol conversion rate during fermentation, they could be applied to produce a reducedalcohol wine [3,4]. Some non-Saccharomyces yeasts like Lachancea thermotolerans, Pichia kudriavzevii, and Schizosaccharomyces pombe have shown potential in regulating acidity during wine fermentation, which could be used for improving the quality of must containing excessive or insufficient acidity [5,6,7]. Several strains of Aureobasidium pullulans, Cystofilobasidium capitatum, Cryptococcus saitoi, Rhodosporidiobolus colostri, and Rhodotorula dairenensis have shown great capability of improving the color quality of wines by producing pectinase during fermentation [8]

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Conclusion