Selenium fortification influences aroma formation in cider fermentation: Insights from multidimensional flavor...

This study investigated how selenium fortification, in combination with Pichia kluyveri and Torulaspora delbrueckii fermentation strategies, influenced aroma formation in cider. Multi-platform analyses revealed consistent differences in volatile profiles between selenium-enriched and non-enriched ciders. Among the identified compounds, 2-phenylethyl acetate emerged as a key aroma-active discriminator associated with selenium-enriched samples. Selenium supplementation increased total ester content by 74.5% in simultaneous co-cultures, contributing to enhanced fruity and floral attributes. In P. kluyveri fermentations, acetate and ethyl esters reached 1.4- and 3.6-fold those of non-supplemented samples, respectively. Gene expression and pathway analyses further indicated that selenium supplementation was associated with differential expression of genes related to amino acid catabolism and ester formation. Overall, these findings suggested that selenium supplementation can influence aroma formation in cider and provided a basis for further exploration of selenium-enriched fermentation strategies.