Postharvest partial dehydration of blueberries enhanced blueberry wine aroma via upregulating phenylalanine metabolism and terpene biosynthesis
Postharvest partial dehydration of blueberries can enhance blueberry wine aroma, while the underlying mechanisms remain unclear. In this study, the key odor-active volatiles in blueberry wines fermented from dehydrated blueberries (30% weight loss) were identified via aroma extract dilution analysis. Results showed that increased levels of phenylalanine-derived compounds such as phenylethanol, and terpenes such as linalool and geraniol, primarily led to the enhancement of sweet, floral and fruity aromas of blueberry wines. Postharvest partial dehydration increased the contents of these compounds, which could be linked to the upregulation of VcGOT2 and VcPAR involved in phenylalanine metabolism, and the upregulation of VcDXS, VcHDR and VcTPS involved in terpene biosynthesis. Notably, the upregulated VcTPS encoded a monoterpene synthase responsible for producing linalool. These findings provided insight into the impact of postharvest dehydration on phenylalanine and terpene metabolism in blueberries, offering a reference for improving blueberry wine aroma through postharvest partial dehydration techniques.