The roles of different photoselective nets in the targeted regulation of metabolite accumulation, wine aroma and sensory profiles in warm viticulture regions.

To improve the quality of grapes and wine in warm viticulture regions, the effects of pearl, red and black photoselective nets on the quality of grapes and wine were systematically investigated. Compared with the CK (open field), three nets improved the microclimate conditions and reduced grape sugar and wine alcohol levels. However, the nets differentially affected other quality profiles of the grapes and wine. The pearl net reduced the total flavanol contents in grapes and total aromatic volatiles in wine. The red net increased the total flavanol, tannin and total aromatic volatile contents in wine by approximately 40%, 95% and 10%, respectively, and the percentages for the black net were 30%, 45% and 3%, respectively. The red and pearl nets were more inclined to improve the taste and aroma sensory qualities of wine than the black net did. The red net had the highest comprehensive scores via principal component analysis.

Effect of foliar application of fulvic acid antitranspirant on sugar accumulation, phenolic profiles and aroma qualities of Cabernet Sauvignon and Riesling grapes and wines.

This study investigated the effects of foliar application of fulvic acid antitranspirant (FA-AT) on Cabernet Sauvignon (CS) and Riesling grapes and wines in a warm viticulture region of China. FA-AT controlled the contents of total soluble solids, fructose and glucose in mature grapes and alcohol in wines. FA-AT improved total phenols and flavonoids in Riesling grapes, and total tannin and individual flavanols in CS grapes and wine, while reducing total individual phenolic acids and flavonols in CS wine. Increased volatiles in CS grapes (hexyl acetate, linalool) and wine (isoamyl alcohol, 1-hexanol, 2-phenylethanol) detected by SPME-GC-MS can contribute to the fruity and floral aroma. FA-AT reduced the accumulation of anthocyanins in CS grapes and wine without an eventual reduction in the tonality of wine by sensory analysis, and improved the taste and balance of Riesling wine. Overall, FA-AT can improve the quality of grapes and wines produced in warm viticulture regions.