Short communicationEvaluation of the performance of Torulaspora delbrueckii, Williopsis saturnus, and Kluyveromyces lactis in lychee wine fermentation

- These three non-Saccharomyces yeast scould partially retain terpenes and terpenoids.
- T. delbrueckii had the highest fermentative capacity and the highest production of ethanol, higher alcohols and ethyl esters.
- W. saturnus produced the highest levels of acetate esters, but ethanol was lowest.
- K. lactis had the greatest ability to retain geraniol and citronellol.
- T. delbrueckii PRELUDE was a promising strain for lychee wine fermentation.

This study evaluated the effects of three non-Saccharomyces yeasts, namely Torulaspora delbrueckii PRELUDE, Williopsis saturnus NCYC22, and Kluyveromyces lactis KL71 on lychee juice fermentation. The fermentation performance of these non-Saccharomyces yeasts was significantly different. T. delbrueckii PRELUDE had the fastest rate of growth and high sugar consumption. W. saturnus NCYC22 used the lowest amount of sugars, but consumed the highest amount of nitrogen. Correspondingly, strain PRELUDE produced the highest level of ethanol (7.6% v/v), followed by strain KL71 (3.4% v/v) and strain NCYC22 (0.8% v/v). Aroma character-impact terpenes and terpenoids could be partially retained in all lychee wines, with higher odour activity values (OAVs) of geraniol and citronellol in strain KL71. However, strain KL71 and strain NCYC22 over-produced ethyl acetate. Strain PRELUDE had a better ability to generate high levels of ethanol, isoamyl alcohol, 2-phenylethyl alcohol, ethyl octanoate, and ethyl decanoate and retained high OAVs of lychee aroma-character compounds cis-rose oxide (16.5) and linalool (3.5). Thus, it is deemed to be a promising non-Saccharomyces yeast for lychee wine fermentation.