Non-Saccharomyces yeasts highly contribute to characterisation of flavour profiles in greengage fermentation

Non-Saccharomyces yeasts play an important role in greengage fermentation. To obtain practical non-Saccharomyces yeasts for high-acid fermentation environments, and improve the flavour quality of fermented greengage beverage, four indigenous acid-tolerant non-Saccharomyces yeast strains were used to conduct greengage fermentation. Hanseniaspora occidentalis, Pichia terricola, and Issatchenkia orientalis were competitively fermentable and significantly decreased the concentration of citric acid and malic acid. HS-SPME and GC-MS were used to analyse the aroma profiles, and results showed that H. occidentalis has potential to produce explicit fruity aroma, since the fermented beverages obtained more esters. Moreover, phenolic acids had the highest concentration among polyphenols of fermented greengage beverage. Comparatively, spontaneous fermentation produced higher levels of most polyphenols, whereas P. terricola treatment resulted predominantly in partial phenolic acids. Kendall coefficients indicated that procyanidins and glycosidic bound flavonols significantly positively correlated with more than 30% volatiles. This study verified the biofunctions of non-Saccharomyces yeasts and applied their potential for flavour improvement in the production of high-acidity fermented fruit beverages.