Evaluation of the potential astringency of the skins and seeds of different grape varieties based on polyphenol/protein binding

Abstract

The potential astringency of eight grape cultivars was evaluated based on polyphenol/protein binding. The parameters such as weights, sizes, total phenols, flavanols and tannins of different grape tissues were determined, and the polyphenol/protein binding was analyzed by SDS-PAGE and spectroscopy. The Cabernet Sauvignon had the highest skin proportion, while the Blue French had the highest seed proportion. The Blue French seeds had the highest total phenolic content, while the Cabernet Sauvignon skins had the highest total phenolic content. SDS-PAGE showed that the seed extracts had a better affinity than skin extracts for saliva proteins, but fluorescence spectra demonstrated that the interactions of skin polyphenols with protein were more complex. These results may provide some useful information on grape potential astringency's evaluation and wine-making in China. Practical Application:This study may facilitate the evaluation of potential astringency of grapes and the improvement of quality wine.

In Vitro and In Silico Interaction Studies with Red Wine Polyphenols against Different Proteins from Human Serum

“…The fluorescence emission spectra of BSA with three kinds of grape varieties-Cabernet Sauvignon, Merlot, and Cabernet Gernischet-were obtained upon the addition of the skin and seed extracts; the fluorescence quenching of BSA in the presence of extracts from grape skins and seeds was evaluated by using fluorescence spectrometry based on simulated conditions of human physiological conditions (pH = 7.4) in order to study the phenolics. A decrease in the fluorescence intensity caused by the quenching of the skin and seed extracts was observed, which is in line with the action of red wine polyphenols [30]. The presence of phenolic compounds can make a great contribution to the perception of astringency in red wines based on their interactions with proteins.…”

Evolution of Physicochemical Properties and Phenolic Maturity of Vilana, Vidiano, Kotsifali and Mandilari Wine Grape Cultivars (Vitis vinifera L.) during Ripening

“…The phenolic profile of grapes depends on many factors, such as variety, maturity, genetic variability, microclimate, environmental stress and agricultural practices applied in the field [8,9]. About two-thirds of grape phenolics are located in the seeds, about one-third in the skin, and only a small percentage is found in the pulp [10,11]. However, phenolic concentration varies depending on the stage of ripening [12][13][14].…”