Contribution of non-Saccharomyces yeasts to aroma-active compound production, phenolic composition and sensory profile in Chinese Vidal icewine

To acquire candidate non-Saccharomyces strains for preparation of high-quality Vidal icewine, 11 representative indigenous non-Saccharomyces strains were selected for analyzing their production of organic acids, phenolic compounds, aroma-active compounds and evaluating their sensory profile in Vidal juice. The results showed that the contents of organic acids in the wines were controlled and balanced well by the non-Saccharomyces strains as well as polyphenol concentrations were well improved during the fermentation. The strains differed from each other in their ability to produce aroma compounds, causing diversity and complexity of aroma characteristics in wine. Fermentation by Saccharomycopsis crataegensis YC30 (Sc) and Hanseniaspora uvarum QTX22 (Hu) could enhance the sweet and floral notes in Vidal icewine, especially Sc, which has never been reported before. It can not only enrich the aroma categories, but also increase the content of delta-decalactone, gamma-decalactone, ethyl isobutyrate, ethyl butyrate, phenethyl acetic acid, etc. The evaluation and optimization of non-Saccharomyces yeast strains could provide theoretical basis for the improvement of ice wine quality, and supply new ideas and strategies for the brewing of ice wine.