Study On Oligomeric Proanhocyanidins In The Grape Seeds

This thesis studied with the extraction acts and crafts of the OPC's from the red grape seeds in the Guangxia wine factory of Ningxia. The contents of OPC's were evaluated by spectrophotometric determination of the vanillin-hydrochloric acid method at 500nm. By a great deal of experiments, the separation process of proanthocyanidins from the red grape seeds was established. The process is composed of five parts: extraction, precipitation, column chromatography, analyze and characteristic measurement.In extraction process, five extraction conditions were studied: temperature, extracting time, concentration of solvent, amount of solvent and ratio of solvent to grape seed. With the extraction yield of Oligomeric Proanthocyanidins and the selectivity of extraction as optimal condition, the optimal extraction conditions are as followed: solvent 60% ethanol, temperature 50℃,solvent volume to grape seeds weight is 7:1, extracting for 3 times, and the time is 30min respectively.After removed the protein of the contents, the fractionation by extraction with ethyl acetate and the precipitation of Oligomeric Proanthocyanidins from the solution by addition of ligroin can refine the contents. The process includes that temperature 0℃, the rate of ethyl acetate and water 3:1,the volume of ligroin 300%, precipitating for two times.Using AB-8 macro porous adsorption resin with column chromatography, it was revealed that the contents can be purified; the content of Oligomeric Proanthocyanidins in product is 92.7%, the extraction yield of Oligomeric Proanthocyanidins was about 1.87 %(100g grape seeds).The separation of Oligomeric Proanthocyanidins by TLC was studied. After the experiments of various ascending elusions, the chromatography was carried out using an ascending elution with toluene: acetone: acetic acid=3:3:1. HPLC was also employed to analyze the composing of each fraction obtained from TLC.OPC's possesses a variety of physiological activities such as antioxidant. It was made sure that the antioxidant of the product is higher than Vc and Ve. The antioxidant will be increased with the amount of addition from 0 to 2000ppm.