Study On Extraction,purification And Properties Of Proanthocyanidins From Grape Seeds

Procyanidins widely exists in plants is a kind of natural polyphenol compounds,which has antioxidant,antibacterial,anti-cancer and other functions.In this paper,Xinjiang Hairuisheng biological engineering company provides Xinjiang white grape seeds as experimental raw materials to research the extraction process,purification,antibacterial activity and stability.The main results are as follows:1? Procyanidins content for the purpose of extract.On the basis of Single-factor test,Box-Behnken design experiment was conducted to design the response surface analysis.Influences of four main factors(solid-liquid ratio,microwave time,microwave temperature and cellulose dosage)on the extraction rate of procyanidins were investigated by response surface analysis.We established the regression model of microwave and enzyme-assisted extraction of grape seed procyanidins.Established model can better reflect the extraction effect of procyanidins.The optimal extraction condition was as followed: temperature 60 °C,solid-liquid ratio 1:14.6(g:m L),microwave time 9 min,cellulose dosage 0.56 mg/m L.Under the above conditions,the extraction yield of procyanidins was 5.72%.2? Using static adsorption method selected the best type of resin from eight types of macroporous resin.By dynamic adsorption method,exploring the pH,temperature,sample rate,sample liquid concentration how to influence the adsorption performance.As well as,studying temperature,volume of eluant and elution speed influenced the performance of desorption.Experiments showed that using AB-8 macroporous resin was better for adsorption and desorption effect of procyanidins.The results showed that the adsorption effect was better when the PH was 3,the temperature was 40°C,the sample speed was 0.3 BV/h,and the sample liquid concentration was 2 mg/m L.Meanwhile,desorption effect was better when the temperature was 40 °C,the elution volume was 2 BV,and the elution rate was 1.5 BV/h.3?Using the Oxford Cup and tube double dilution method researchs the bacteriostatic effect of grape seed procyanidins.The results showed that procyanidins had no inhibitory effect on Escherichia coli,and the inhibitory effect on Staphylococcus aureus was obvious.The inhibitory effect was positively correlated with the grape seed proanthocyanidin concentration.Procyanidins can effectively inhibit the growth of staphylococcus aureus after purification: bacteriostatic ring 19.2 mm,minimal inhibitory concentration(MIC)2.5 mg/m L,minimum bactericidal concentration(MBC)5 mg/m L.After treated with procyanidins,permeability of cellular membrane was increased,and cell wall was destroyed.Scanning electron microscope photograph showed the bacterial surface was wrinkled and size of cells was different.4?Studying the effects of pH,light,temperature and metal cations on grape seed proanthocyanidins by testing the residual rate of proanthocyanidins.The results showed that proanthocyanidins were sensitive to light,temperature and metal cations.So proanthocyanidins should be protected from light,low temperature and metalware.