Study On The Polyphenol Extraction Methods And Total Antioxidant Capacity Of Different Pomegranate Verieties

Polyphenols is one of the important functional ingredients in pomegranates. Five pomegranate varieties produced in Shaanxi Lintong area and one from Sichuan Panzhihua as test materials, the experiment was conducted to study on polyphenol extraction technology and polyphenol content and antioxidant activity, and aimed to provide theoretical basis for the comprehensive application and development of pomegranate. 80% of acidification methanol as extraction agents, combined with ultrasonic auxiliary efficacy, through designing single factor tests and orthogonal test, finally it was determined that the best extraction conditions and extraction effect. Important phenolics compounds(total phenol,total flavonoids, OPC and mono- phenolics) and antioxidant activity(DPPH, CUPRAC, PFRAP, SRSA)were evaluated in pomegranate peel, inner diaphragm and pomegranate seed. At the last, we have the single variety winemaking experiment use the six pomegranates varieties.It could be concluded from this experiment:(1)The optimal process of extraction of the total polyphenols from granatum with ultrasonic wave(fixed power 100W) were as follows: radio of solid to liquid 1:20(g/mL), temperature 30℃, extracting duration 20 min, once ultrasonic extraction process. The extracting rate of total polyphenol was 14.06mg/g.(2)Measuring important phenolic compounds in pomegranate peels, inner diaphram and seeds. It indicated that Total polyphenol and the flavonoids content presents the same regularity. The pomegranate peels has the highest levels, second one is in the diaphragm. The lowest part is in pomegranate seed. Total phenolic compounds (TP)in pomegranate peels, diaphragm and seeds ranged from 1.07 to 13.86 mg gallic acid equivalents g. Total Flavonoids (TFO) in pomegranate peels, diaphragm and seeds ranged from 0.41 to 11.98 mg catechins acid equivalents g. Proanthocyanidin (PC) ranged from 0 to 5.57 mg catechins acid equivalents g. Composition and content analysis showed that Pomegranate peels and diaphragm is rich in polyphenols. Ten components had been identified in different extracts,and the major components is gallic acid with the content of 2358.67mg/g, followed by less contents of benzoic acid, catechin, caffeic acid and ferulic acid etc. The content of mono-polyphenols in others is all low.(3)The anti-oxidation ability of each sample were measured. It indicated that peel, inner diaphragm and seeds of superoxide radical scavenging capacity and DPPH clear ability to converge. Polyphenols extracted from different organizations parts of pomegranate has different antioxidant capacity respectively. Superoxide Radical Scavenging Activity ranged from 45.75 to 86.19%. DPPH Radical Scavenging Capacity ranged from 79.67 to 90.9%. Potassium Ferricyanide Reducing Power (PFRAP) and Cupric Reducing Antioxidant Power (CUPRAC) ranged from 46.62 to 456.49 and 50.63 to 376.88 mg of trolox equivalents g, respectively.(4)For single variety pomegranate wine, after tasting team senses tasting, integrated highest scoring is Luyidan, next is Panzhihua, and then Sanbaitian, Ddanhongtian, Jingpitian and Sour pomegranates.