Studies On Extraction, Purification And Antioxidant Activity Of Trans-resveratrol In Brewing Grape Wine Dregs

In this experiment, it is aimed chiefly at developing and utilizing skin and residues of grape which was wine by-product in industrial production, exploring the technology of reclaiming trans-resveratrol from it, and researching the physiological activity. The extraction and purification methods of trans-resveratrol were researched, and we researched antioxidant activity of trans-resveratrol. Through researching, it give theoretical basis and some scientific message for the recycling of skin and residues of grape.The determination methods of trans-resveratrol was established. Trans-resveratrol was determined by high performance liquid chromatography (HPLC). The optimal chromatography conditions were obtained with methanol/water (45:55,v/v) as flow phase, flow ratio(0.8mL/min);column temperature choosed room temperature. Under these conditions, the separation effect was preferable, a good peak-shape was obtained,the linear relationship was excellent with concertration of trans-resveratrol in the range of 1μg/mL～20μg/mL,the minimum detection limit was 1μg/mL. Trans-resveratrol was determined by spectrophotometry method, the biggest absorbtion wavelength (306nm) were firstly obtained,the absorbance presented a linear relationship with concentration of trans-resveratrol in the range of 0～8μg/mL.The solubility experiments was established in different temperature and solvent.The results showed that trans-resveratrol had the best solubility when acetone was solvent during 20℃～60℃. The stability experiments of trans-resveratrol showed that the UV spectrum was greatly changed after trans-resveratrol was placed in UV light or sunlight for 15 minute, trans-resveratrol was badly destroyed. Trans-resveratrol showed decreasing trend during 24 hours even if without lighting, but total loss content was much smaller than in the sunlight. So we should adopt avoiding sunlight method when extraction and purification of trans-resveratrol was made, and it is very necessary to use drying in the shade for raw materials,otherwise it would destroy much trans-resveratrol.Trans-resveratrol was extracted by alcohol reflux extraction and ultrasonic extraction from brewing grape wine dregs.The appropriate conditions of alcohol reflux extraction were obtained,namely extracted for 5h by using 80% ethanol solution at 60℃with the material ratiol of 1:20(g/mL).The contents of trans-resveratrol was 94.2μg/g. The optimal process of ultrasonic extraction were obtained, namely extracted for 50min by using 80% ethanol solution at 350W with the material ratiol of 1:15(g/mL). The content of trans-resveratrol was 133.2μg/g. Compared the results we found that ultrasonic extraction was preferable method because it led to higher yield ratio, less solvent, and shorter extraction time.Purification technology was studied by using the combinative method of ultrafiltration and precipitation, and the optimal process of purification were obtained. Namely ultrafiltration conditions were that the ultrafiltration membrane molecular weight cut-off (MWCO) was 10000, the ultrafiltration...