Influence of berry ripeness on seed tannins extraction in wine

A New Approach to the Reduction of Alcohol Content in Red Wines: The Use of High-Power Ultrasounds

“…From these observations, the concept of phenolic maturity has appeared at the grape stage, where the skin phenolic content is not only high, but also easily extracted, and seed tannin extraction is reduced due to a lignification of the seed [ 3 ]. When grapes are phenolically immature, the skin phenolic compounds are not easily extracted, even when present at high concentration, yet high concentrations of the astringent seed tannins can be present [ 4 , 5 ]. This situation changes when phenolic maturity is reached, cell walls are easily degraded, and phenolic compounds are extracted [ 2 ].…”

Changes in the flavan-3-ol and polysaccharide content during the fermentation of <i>Vitis vinifera</i> Cabernet-Sauvignon and cold-hardy <i>Vitis</i> varieties Frontenac and Frontenac blanc

“…The tannin content and composition of the grape skin and seed of all three varieties, as well as their cell wall structure (involved in tannin diffusion and retention in wine) could explain those differences. The winemaking process (e.g., maceration time and temperature), which was similar for all cultivars in this study and the alcohol content (e.g., involved in disorganization of seed protection outer lipidic layer), which differed along the AFM between varieties, also play an important role on cell wall disruption and, therefore, the percentage of extractable tannins from grape seeds and skins (Rousserie et al, 2019).…”

Extended Harvest Date Alter Flavonoid Composition and Chromatic Characteristics of Plavac Mali (Vitis vinifera L.) Grape Berries

“…Moreover, this is favored by a minimal impact of green harvest wine (GHW) on wine polyphenols that is function of lower wine pH [ 13 ]; non-beneficial is a significant decrease in SO 2 -resistant pigments, especially in the case of greater amount of 43% juice substituted with GHW [ 11 ]; however, the inability to sensorially distinguish those wines from regular ones [ 13 ], and the fact that differences in SO 2 -resistant pigment fade away after 18 months of bottling age [ 11 ], makes them interesting in optimization of acid part must matrix wine before fermentation. Furthermore, this is supported with a higher amount of non-extractable tannins (25%) in under-ripe versus ripe (18%) seeds and lower amount of tannin extracted from under ripe (72%) versus ripe seeds (77%) [ 14 ]. A lower concentration of available polyphenols, particularly anthocyanins, flavonols and flavon-3-ol monomers and a lack of reduction factors Nicotinamide adenine dinucleotide(NADH) or Nicotinamide adenine dinucleotide phosphate (NADPH) caused by a strong amino acid metabolism, is a potential problem of GHW and early harvest dates that leads to production of wines high in acetaldehydes [ 25 ].…”

“…At the ripening timeline, synchronization of those processes between berries at the cluster level occurs [ 10 ], although a certain degree (10%) of heterogeneity lags behind even in extended harvest dates [ 11 ]. The enological potential of the berries depends on the quantitative and qualitative polyphenolic profile of the berries in the time of harvest [ 1 , 12 , 13 ] and their extraction during vinification [ 3 , 5 , 14 ]. Harvest before berries reached technological maturity, known as cessation of active sugar accumulation, is associated with fresh wines, low in alcohol, high in acids, with a light and vivid color, thin body, bitter taste and astringent sensations [ 1 , 13 ].…”

“…Wines produced from grapes that did not reach phenolic ripeness are less colored and more bitter and astringent, due to reduced anthocyanin and skin proanthocyanidin and greater seed proanthocyanidin extractability [ 13 ], which negatively influences the sensory profile of wine [ 28 ]. Harvest beyond phenolic ripeness to achieve better coloration and velvety tannins often results in unbalanced wines high in alcohol, low acid content, and high pH, with a higher proportion of seed proanthocyanidin extraction linked to wine matrix composition [ 11 , 14 ]. Such wines are also associated with sluggish fermentation or problematic malolactic fermentation and reduced wine aromatic potential without must N-supplementation [ 1 ].…”