Study On Extraction Procession Of Resveratrol

Extracting techniques is experimentally studied by using methods of alcohol-extraction, cellulose-assisted extraction, microwave-assisted extraction and ultrasonic-assisted extraction for Polygonum cuspidatum. According the content of resveratrol that is extracted from Polygonum cuspidatum measured by the ultraviolet radiation method, the extracting yield is gained. And the extracting effect infected by the technical parameters of each method is discussed.Through series experiments designed according univariate experiments,According to the univariate experiments,the orthogonal experiments are carried out to analysis individually the main factors influencing the resveratrol yield, the effects of temperature, extracting time, alcohol dosage and alcohol concentration of extracting solution on resveratrol yield are studied in alcohol-extraction method. The results show that the extracting time of extracting solution is the most effective factor. In cellulase-assisted extraction experiment,the effects of cellulose amount, temperature , extracting time, and pH of extracting solution on resveratrol yield are studied .The results show that the temperature of extracting solution is the most effective factor.In microwave-assisted extraction experiment, the effects of microwave power, actuation time, alcohol dosage, alcohol concentration of extracting solution on the resveratrol yield are analyzed, alcohol concentration are found to be remarkable influence factors. In ultrasonic-assisted extraction experiment, the effects of temperature, extracting time, alcohol dosage, alcohol concentration of extracting solution on the resveratrol yield are analyzed, alcohol concentration are found to be remarkable influence factors. Furthermore the results of these experiments indicate that both grinding and pre-soakage can improve the Astragaloside IV yield considerably.By comparing extraction yield of the above four extraction methods, the cellulase-assisted extraction, microwave-assisted extraction and ultrasonic-assisted extraction method is considered as the better three than the alcohol-extraction.Gentle extraction conditions ,which were determined experimently as follows : cellulase-assisted extraction : cellulose amount 5.000g, temperature 50℃, extracting time 90min, and pH 5.0 ; microwave-assisted extraction: microwave power 510W, actuation time 60s, alcohol dosage 1:20, alcohol concentration 80% ; ultrasonic-assisted extraction: extraction temperature 50℃, extraction time 10 min and the alcohol concent ration 1:20. Compared with traditional extracting technology by ethenol ,extraction yield of resveratrol was increased by about 3 times by using this ultrasonic extraction technology.