Selection and characterization of indigenous yeasts to enhance fig wine fermentation and aroma profiles

Indigenous yeasts may improve the sensory quality and regional character of fruit wines, but their performance needs to be evaluated in the intended fruit matrix. In this study, 130 yeast isolates representing 13 species were recovered from the surfaces and spontaneous fermentations of four fig cultivars grown in Shaanxi, China. The collection comprised 43 Saccharomyces cerevisiae (SC) and 87 non-Saccharomyces (NS) isolates. Following preliminary growth and stress-tolerance screening, six indigenous isolates were tested in synthetic must, and four were subsequently evaluated in fig must. S. cerevisiae ZZB23 began fermenting rapidly, grew at 12% (v/v) ethanol, and produced fewer higher alcohols than the commercial control CECA (252.16 vs. 345.70 mg/L). Sensory analysis also indicated more pronounced floral and fruity notes. In sequential fermentation, Hanseniaspora uvarum JAFA13 produced 0.82 g/L acetic acid in synthetic must, and combined higher ester production with lower higher-alcohol production. Its unpleasant-aroma score was lower than that of JAFB28 (18.708 vs. 26.591). PLS-DA identified 15 volatile compounds that contributed most strongly to separation among the wines. Overall, ZZB23 and JAFA13 were selected as promising indigenous starter candidates for fig wine production, with ZZB23 showing favorable fermentation performance and sensory characteristics and JAFA13 providing potential advantages for aroma modulation in sequential fermentation.