Optimum Treatment Of Extracting Proanthcyanidins From Grape Seeds And Analysis Its Radical Scavenging Activities

Grape seed take for most part of the wine waste, and its accounts for about4%-7%ofgrape total weight. The most important functional ingredients in grape seed is polyphenols,most part of which is flavonoids and it have an important impact on wine quality. Winepolyphenols have hundreds of structures, and have a great influence on wine aroma, color andtaste. Studies showed that polyphenols take an important part on human health, especially inthe area of antioxidant and anti-aging.The study using Accelerated Solvent Extractor （ASE） carried on a detailed research forextracting proanthocyanins from grape seeds. With the ultrasonic extraction method, weanalysis the purity, extraction rate, DPPH, Scavenging superoxide anion free radical ability,and the relationship between extraction rate and purity.The results were as follows:1. After using design expert V7.1.6statistical software multivariate regression analysis,we get the quadratic regression model:PC%（proanthocyanidins extraction rate）=-41.6348＋1.8998Z₁＋0.114948Z₂－0.29658Z₃－0.592458Z₄－0.000288Z₁×Z₂＋0.002095Z₁×Z₃－0.010315Z₁×Z₄＋0.0001425Z₂×Z₃＋0.00097125Z₂×Z₄＋0.005415Z₃×Z₄－0.035358×Z₁²－0.000086258×Z₂²－0.001860833×Z₃²－0.004629583×Z₄²According to the model, the four factors effect the grape seed proanthcyanidins rate areshowed as follows: Extraction time（Z₁）> Temperature（Z₄）> Volume（Z₃）> Pressure（Z₂）. Theoptimal conditions are showed as follows: extraction temperature79.99℃, extractionpressure1161.25psi, methanol concentration79.99%and extract time12.83min. Under suchconditions, the extraction yield of proanthocyanidins was6.817%. After three times ofextraction, results showed6.286%, and the purity was41.02%. And there have a linearrelationship between the extraction rate （y） and the purity （x）. The regression linear equationis showed as follows: y=5.8487x+6.1906, R²=0.8176, compared to4.045%and28.48%byultrasonic method.2. The product color from ASE painted light rose, and more light than ultrasonic productcolor. With the same weight of sample, the OPC’s contents are showed as follows: ASE product> Ultrasonic wave product> Crude extraction product.3. In the antioxidant ability, when proanthcyanidins have the same content, ASE methodhas a better effect than ultrasonic method, which proves that the accelerated solvent sample ismore pure, and has a higher antioxidant capacity.