Post-veraison sunlight supplementation improved the phenolic profile of Cabernet Gernischt (Vitis vinifera L.) grape and wine in a temperate monsoon climate

Abstract

The regulation of solar radiation is a pivotal agricultural practice in enhancing the quality of grapes and subsequently, wine. In regions like Yantai, where solar radiation levels are typically low, the accumulation of wine phenolic compounds is negatively impacted. In light of this, our study sought to assess the efficacy of silver reflective mulch (RM) treatment on grape yield, maturity, and phenolic composition. Specifically, we applied RM treatment post-veraison to a Cabernet Gernischt (Vitis vinifera L.) vineyard in the Yantai wine region of China. Our findings indicate a consistent improvement in grape maturity with RM treatment, alongside enhanced accumulation of total phenols (TP), total tannins (TT), and total anthocyanins (TAC) in grape skin. Consequently, this led to elevated levels of phenolic compounds in wines and heightened color intensity. Moreover, tandem mass spectrometry analysis unveiled higher concentrations of key compounds such as petunidin-3-glucoside, malvidin-3-glucoside, procyanidin B1, quercetin-3-glucoside, cis-resveratrol, and piceatannol in the resultant wines. This study underscores the potential of RM treatment to bolster wine phenolics, particularly in regions characterized by a Temperate Monsoon Climate.