Extraction,Purification And Functional Characteristics Of Pear Polyphenols

In this study,pear polyphenols were extracted using the solvent extraction method,and the efficiency of extraction solvents methanol,ethanol and water was compared;The pear polyphenols were purified with 5 kinds of macroporous resins.The optimum resin and optimal purification process were selected;The antioxidant activity of pear polyphenols was determined using four types of antioxidant activity evaluation method;The rats were lavaged with pear polyphenols extracted by 3 different solvents,and some indexes in serum and tissues were determined to study the functional characteristics of pear fruit polyphenol.The results are as follows:1.The pear polyphenols were extracted with methanol,ethanol and water and the extraction efficiency was compared.Ethanol was the most efficient solvent,the extraction rate was 1.011 mg/g,extremely significantly higher than that of methanol solvent and water solvent;Extraction rate of water solvent was the lowest and it was only 0.365mg/g.2.The results showed that NKA-9 resin had the best performance of purifying pear polyphenols extracts of all the five resins by comprehensive analysis of the adsorption and desorption study.The optimum condition of NKA-9 resin was as follows:the sample concentration,2 mg/mL;the sample pH,5.0;the sample flow rate,1 mL/min;eluent ethanol concentration,70%;elution velocity,1 mL/min;Under this condition,the purity of the pear polyphenols increased from 6.23%to 30.68%.3.The results of antioxidant activity of pear fruit polyphenols showed:The pear polyphenols extracted with methanol,ethanol and water solvent all had the ability of scavenging DPPH radicals,ABTS radicals and oxynitroso.It proved that the pear fruit polyphenols had the antioxidant capacity.The scavenging ability was enhanced gradually with the increase of polyphenols concentration.The pear fruit polyphenols extracted by ethanol solvent had the strongest antioxidant ability.4.The rats were lavaged with pear polyphenols extracted by 3 different solvents,and some indexes in serum and tissues were determined to study the functional characteristics of pear polyphenols.The results are as follows:pear polyphenols extracted by 3 different solvents could all enhance the vitality of SOD,AOC and increased the content of HDL-C in serum.They could also reduce the vitality of ALT,AST and decreased the content of MDA,TC,TG and LDL-C in serum.At the same time,pear polyphenols could enhance the vitality of SOD and AOC in liver,kidney and intestine tissue.They could also decrease the content of MDA,IL-1?,IL-2,IL-4,IL-10,TNF-a and IFN-y in liver,kidney and intestine tissue.The pear polyphenols extracted with ethanol solvent was the best in the three solvents.It can reach significant or extremely significant level in these indexes.The above results showed that the pear polyphenols had the functional characteristics of improving the antioxidant activity,lowering the cholesterol,protecting the liver,enhancing the immunity.