Study on the extraction of polyphenol from grapevine branch by ultrasonic adjunct extraction method.

【Objective】 The aim of the study was to investigate the best extracting condition of polyphenol from grapevine branch by ultrasonic adjunct extraction method.And the different contents of polyphenol from eight grapevine cultivars' branches were compared via this method.【Method】 Influences of extracting power of polyphenol were investigated by single factor test.The infected factors were ethyl alcohol density,extracting temperature,ratio of solid to liquid,ultrasonic time and extracting times.While the orthogonal test was devised to determine the best extracting condition based on the single factor experiment,the polyphenol content of annual grapevine branches that belonged to eight different varieties was reviewed by the extracting conditions.【Result】 The best extracting condition of polyphenol from grapevine branch by ultrasonic adjunct extraction method was as follows:60% ethanol as solvent,ratio of solid to liquid 1∶12,ultrasonic time 30 min,extracting temperature 20 ℃ and extracting times 2.And the yield of total polphenol was 97.38%.The polyphenol content of one-year-old grapevine branches that belonged to eight different varieties exceeded 20 mg/g.The content of polphenol of the Cabernet Franc(32.855 4 mg/g) was the highest in the eight different varieties,the Merlot(31.967 7 mg/g) lower,the 8804 the lowest(20.815 6 mg/g).【Conclusion】 The suitable conditions of polyphenol from one-year-old grapevine branches by ultrasonic adjunct extraction method were determined.And the yield of total polphenol was 97.38%.