Effect of aging time, dosage and toasting level of oak chips on the color parameters, phenolic compounds and antioxidant activity of red wines (var. Fetească neagră)

Alternative oenological practices are a key factor in sustainable winemaking. The influence of 6 types of chips with different toasting degrees on chromatic parameters, phenolic families and antioxidant activity of Fetească neagră wines has been studied. Brownish hue was highly influenced by the aging time and increased the most in wines treated with chips of high toasting degree. Color saturation was influenced by the type of chips but neither the aging time nor the dose of chips modifies significantly this parameter. Phenolic acids and catechins decreased with the aging time, whereas flavonols, anthocyanins and high molecular weight procyanidins increased; the antioxidant activity was related to the dosage of chips and the aging time. Chemometric analyses showed a clear difference among the wines aged for three months with chips of different degrees of toast, whereas the differences at 1.5 months of aging were irrelevant. The wines aged with chips of low toast degree showed the highest phenolic content, highlighting the phenolic families related to color properties (anthocyanins and colored pigments) and to astringency (tannin of high molecular weight). Therefore, these types of chips accelerated the aging process of the wine.