The Effects of Temperature and Ethanol on Proanthocyanidin Adsorption to Grape Cell Wall Material in the Presence of Anthocyanins

Abstract

The quantitative and qualitative impacts of anthocyanins on proanthocyanidin adsorption to grape-derived cell wall material were investigated in fifteen unique systems of varying temperatures, ethanol concentrations, and proanthocyanidin concentrations. Proanthocyanidin solutions were exposed to cell wall material and monitored for changes in concentration over 24 h. Increases in both temperature and ethanol resulted in a larger retention of proanthocyanidins in solution and typically faster adsorption kinetics. Analysis of the solution after exposure to cell wall revealed a significant reduction in the molecular weight of proanthocyanidins present in solution, suggesting that anthocyanins do not alter a previously described mechanism of preferentially binding large molecular weight molecules. Additionally, a reduction in polymeric pigment abundance was noted in most conditions, suggesting rapid formation of polymeric pigment in the model solution and preferential adsorption of the polymeric pigment to cell wall material. Compared to a previous study of proanthocyanidin adsorption in the absence of anthocyanins, a significantly larger percentage of proanthocyanidin material was lost via adsorption—up to 70% of available material. In a winemaking context, this may suggest a preferential loss of polymeric pigment via adsorption to cap cell wall material compared to non-pigmented proanthocyanidins and free anthocyanins.

Exploration of grape pomace peels and amaranth flours as functional ingredients in the elaboration of breads: phenolic composition, bioaccessibility, and antioxidant activity

“…Also, the adsorption of proanthocyanidins to the cell wall material decreases with increasing temperature and ethanol concentration in the system, as in breads. 66 In the MeOH/HCl extracts, the flavanols were the most abundant compounds (Fig. 3B), being EGC the major in all cases (33, 62, 51, and 74 mg g −1 d.m.…”

Influence of Grape Flesh on the Retention and Composition of Polyphenols from Skins and Seeds

“…Conversely, the detection of large polymeric pigments (LPP) was either absent or negligible in the supernatant of any tissue combination from Pinot noir tissues, potentially because there were insufficient monomeric anthocyanins or tannin with larger mDP (>4) to form large enough polymeric pigments to precipitate in the presence of bovine serum albumin . Furthermore, the absence of acetaldehyde might contribute to the slower rate of polymeric pigment formation, as it has been reported using comparable model wine systems …”

“…The released free glucose molecules are then derivatized with the reagent PMP, forming sugar–PMP derivatives for subsequent detection and quantification . Notably, the SK + SD + F conditions of Marquette and Frontenac grapes exhibited the highest mole % of glucose, which could be associated with the preferential adsorption of both the monomeric anthocyanins and polymeric pigments to polysaccharides …”

“…47 Notably, the SK + SD + F conditions of Marquette and Frontenac grapes exhibited the highest mole % of glucose, which could be associated with the preferential adsorption of both the monomeric anthocyanins and polymeric pigments to polysaccharides. 39 No difference in total soluble polysaccharide concentrations between cultivars was observed under the same conditions. In terms of the effects of different tissue conditions, the soluble polysaccharide concentrations in the Pinot Noir supernatant had no significant difference across all three conditions.…”

The Application of Ultrasound and Enzymes Could Be Promising Tools for Recovering Polyphenols during the Aging on Lees Process in Red Winemaking

“…The high temperatures and pressures that are locally reached due to cavitation could help the release of polyphenols adsorbed in the cell walls. Moreover, ultrasound could desorb the polyphenols that are bound to cell walls forming multilayers, as hypothesized by Beaver et al [ 29 ], and this could facilitate the access of the enzymes that degrade the cell wall.…”