The Study Of Inactived Yeast On Quality Characteristics In Red Wine

Yeast cell contains 25% dry matter which including carbohydrates, nitrogenous substances, lipids and minerals. And the yeast’s self-dissolution process can releases polysaccharides, amino acids, proteins, nucleotides and some salts. Inactivated yeast handled with treatments of high temperature and could be used to prevent fermentation suspension and restart the fermentation, accelerate the fermentation rate and made the fermentation more fully.The polysaccharides of yeast cell wall can promote fermentation in winemaking and be usful for malic acid lactic fermentation, color, stability of the wine and increase the complexity of the aroma, which made the wine become more mellow, full and mellow. There were many studies about yeast and polysaccharides, but it is not easy for zymosan to extracted and purified and also inactivated yeast research less. Therefore, this test selected inactivated yeast as factors to be studied by dry red wine physical and chemical indicators, the types and contents of phenolic compounds, antioxidantion, and sensory analysis, etc. to probe the effects of inactivated yeast on wine quality.The results indicated that added inactived yeast in winemaking could reduce the value of total sugar, total acid and tone of wine, but the color value increased and the hightest content of total phenol, total tannin and total anthocyanin were found in processing 2. Eight kinds of phenolic compounds could be detected in wine including ferulic acid, quercetin, caffeic acid,chlorogenic acid, rutin,(+)-catechin, ellagic acid and gallic acid and it could increased the content of phenolic compounds of wine that added inactivated yeast 3 g/L at the 25 th day.The total capacity reducing, the DPPH and ABTS clearance became strongest comparing with others wine in processing 2(added inactivated yeast 3 g/L at the 5th day), which was coincident with the changes in phenolic compounds content.It was detected out 103 kinds of aroma components, including 31 alcohols, 47 esters, 19 kinds of acids and 6 kinds of other substances(ketones, phenols, ethers and aldehydes).Inactivated yeast could increase the types and content of aroma constituents during winemaking, especially for alcohols and esters’ types and contents. Considering sensory evaluation, aroma and sensory quality could be improved in processing 4(added inactivatedyeast 3 g/L at the 15 th day).Thus, inactivated yeast could improve the quality of Cabernet Sauvignon and be used as an additive in winemaking. It is best for wine to adding inactivated yeast with concentration of 3 g/L at the 15 th day(lactic acid malic acid fermentation).