Sequential inoculation of non-Saccharomyces yeasts and Saccharomyces cerevisiae modulates strawberry wine quality: Physicochemical, volatile and sensory analyses

The mixed fermentation of non- Saccharomyces yeasts with Saccharomyces cerevisiae ( S. cerevisiae ) is regarded as a promising strategy to improve the quality of fruit wine. In this study, we investigated the effects of sequential inoculation fermentation involving four non- Saccharomyces yeast species ( Tourlaspora delbrueckii ( T.d. ), Metschnikowia pulcherrima ( M.p. ), Schizosaccharomyces pombe ( S.p. ) and Issatchenkia terricola ( I.t. )) and an S. cerevisiae strain on the physiochemical properties, volatile compounds and sensory profiling of strawberry wine. The sequential fermentations exhibited a significant reduction in ethanol and organic acids content, while free amino acids content increased by 0.28–3.74 times, particularly in the M.p.+S.c. group. The GC-IMS identified 68 volatile compounds, among which isoamyl acetate, ethyl hexanoate, and isobutanol were found to be the predominant volatiles of strawberry wine. Samples more frequently characterized as “strawberry”, “honey” and “preserved fruit” in Check-all-that-apply analysis were preferred by the panelists ( n = 93). The I.t.+S.c. elicited emotional responses of “fascinated” and “surprised” leading to a higher liking rating. Furthermore, the PLSR analysis demonstrated a significant contribution of esters and higher alcohols, such as ethyl 3-methylbutanoate-D, ethyl propanoate, along with isoamyl acetate-D, to the fruity and sweet notes. The present study provided useful information into the mixed inoculation fermentation strategy, which involves combining appropriate non- Saccharomyces yeasts with S. cerevisiae , for developing distinct styles and enhancing the oenological quality of strawberry wine.