Influence of freezing and heating conditions on grape seed flavan-3-ol extractability, oxidation, and galloylation pattern

Abstract

In cool-climate viticulture, the short growing season can influence grape seed maturation by reducing the apparent oxidation of flavan-3-ol monomers and associated increase in seed browning. A reduction in seed maturation increases the potential extraction of flavan-3-ol monomers into wine during maceration operations, heightening bitterness. Here, we carried out a 2 × 2 factorial experiment to test the ability of freezing and heating treatments to advance maturation (decrease flavan-3-ol, improve browning) of (Vitis vinifera L.) Pinot noir and Cabernet Sauvignon seeds over a 24-h incubation period. Only freezing significantly increased seed browning in both cultivars. Subsequent correlations with seed flavan-3-ol monomer concentrations suggest that freezing enhanced the oxidation of these compounds. Interestingly, natural ripening and freezing reduced galloylated flavan-3-ol monomers to a greater extent than non-galloylated ones. This study provides new information regarding the susceptibility of flavan-3-ol monomers to freezing and heating, and also suggests that freezing can advance the maturation the seeds of under-ripe red vinifera grapes.

The effect of eight-week resistance training and consumption of grape seed nanoparticles on mitochondrial biogenesis of heart tissue in the myocardial infarction model

“…Meanwhile, black grape seed extract is one of the supplements that has flavonoid compounds with very high antioxidant effects. The biological properties of polyphenols include antioxidant, anti-cancer, and antiinflammatory effects, among which proanthocyanidin is the most effective anti-oxidant compound of grape seed (15). Zarei et al in 2022 showed the positive and synergistic effects of co-administration of grape seed and regular exercise for 14 weeks to prevent acute and chronic cardiac protective phenomena in heart ischemia rat models (16).…”