| Polysaccharide is the main high molecular weight component in wine,and can reduce the astringency of wine,improve the stability of wine color,protein and tartar,make the taste better.Phenolic compounds are an important functional component in wine,which affects the taste,aroma,color,etc.Some polysaccharides can react with tannin to deactivate tannin and make the wine’s mouth feel better.In order to determine the best range of wine polysaccharides’ effect on wine astringency,the wines made with different proportion of skins and seeds were used as raw material.The effect of polysaccharides on polyphenol/protein interaction was studied by polyacrylamide gel electrophoresis(SDS-PAGE)and fluorescence spectroscopy.The results are as follows:1.A batch of red wine was brewed with different ratio of grape skins and seeds,and the contents of total phenol,total flavanol and polysaccharide were determined.The results showed that the effect of grape skin on the content of polysaccharides in red wine was greater than that of grape seed,and the effect of grape seed on the content of total phenol and total flavanol in red wine was greater than that of grape skin.In addition,the contents of polysaccharides,total phenols and total flavanols in the wines made by different proportion of grape skins and seeds were significantly different.2.The wine polysaccharides extracted by alcohol precipitation contain a lot of pigments,proteins,small molecules and so on,which need to be further purified.Column chromatography can effectively remove the pigment,protein and other substances from crude polysaccharides,thereby increasing the sugar content.When the polysaccharides were separated and purified by macroporous resin,most of the polysaccharides could be eluted with distilled water and the remaining polysaccharides could be eluted with 60%ethanol.The purified polysaccharide wasa yellow powder crystal with a high sugar content,but still contains a small amount of protein.3.According to different degree of polymerization,the phenols in wine were divided into three parts:monophenols,oligomers and polymers by C18 solid phase extraction column.The monophenols standard product,monophenols,oligomer,polymer and the mixture of the three components were dissolved in the model wine buffer.The crude polysaccharides and polysaccharides were added to the model wines according to an appropriate standard.The polyphenol/protein interaction of wine was studied by SDS-PAGE and fluorescence spectrometry.The results showed that when the crude polysaccharides were added to the model wines,the effects of crude polysaccharides on the polyphenol/protein interaction were varied with the phenolic substances.And when the purified polysaccharides were added to the model wines,the effect of polysaccharides on the polyphenol/protein interaction was the greatest while the amount of polysaccharides was 0.2～0.6g/L.4.Made the wines brewed with different proportion of grape skins and seeds as raw material,and the crude polysaccharides and purified polysaccharides were added to the wines at an appropriate standard.Polyacrylamide gel electrophoresis and fluorescence spectrometry were used to study the effect of polysaccharides on polyphenol/protein interaction in wine.The result presented that when adding crude polysaccharides to wine made with different proportion of skins and seeds,the content of crude polysaccharides were changed when it influenced the astringency greatest.But when the amount of purified polysaccharides was 0.2～0.6 g/L,the effect of polysaccharides on wine astringency was the most significant in the wine brewed with different proportion of skins and seeds. |
