Studies On Purification Technology By Zn²⁺,Reducing Blood Lipid And Antimicrobial Effects Of Persimmon Polyphenol

Persimmon(Diospyros kaki Thunb., Ebenaceae, Diospyros L.) is a deciduous tree which is also a economic tree widely cultivated and used as food and medicine for a long time in China. And China is the main producer of persimmon fruits around the world. Persimmon fruit polyphenol exerts verious functions, including antioxidation, anti-atherosclerosis, anti-mutagenesis, antiaging, anticancer and anti-microorganism, etc. which have achieved great attention all over the world. It has been reported that persimmon fruit polyphenol contains gallic acid, proanthocyanidins, ellagic acid, catechin, quercetin, vanillic acid, syringic acid, kaempferol, isodiospyrin, hyperin, etc. and this total polyphenol is more than that in kiwi fruit and apple. Recently, most fruit polyphenol purification techniques are about apple, grape, mango, etc. These techniques are usually column chromatography and ultrafiltration which have many drawbacks like limited application, expensive and time consuming. However, purification of persimmon polyphenol by sedimentation method has not been reported; the utilization of persimmon is focused on food industy and the research of persimmon polyphenol is mainly its antioxidant activity, but the body lipid regulation mechanism and antibacteria activity is rarely reported. In order to make full use of persimmon, we explored a novel purifucation method of persimmon polyohenol which is inexpensive, time-saving, energy-efficient and high yeild. The body lipid regulation mechanism and antibacteria activity of persimmon polyophenol were discussed as well. The results are as follows:(1) The optimum parameters of sedimentation were m(persimmon polyphenol):m(ZnCl2)=1:5, pH6.8,25min and30℃; the optimum parameters of dissolution were:2.5moL/L HC1, m(sediment):v(HCl)=1:5(g:mL),20min and30℃, under this condition, the yield and purity of persimmon polyphenol could reach12%and92.6%, respectively.(2) Persimmon fruit polyphenol could remarkably reduce the levels of serum total triglycerides(TG), total cholesterol(TC), low-density lipoprotein cholesterol(LDL-C), lipid peroxides(LPO) and hepatic free fatty acid (FFA), slightly increase the level of high-density lipoprotein cholesterol(HDL-C) and notably improve the activities of superoxide dismutase (SOD), hepatic lipase(HL) and lipoprotein lipase(LPL).(3) Persimmon polyphenol showed inhibitory effects on Escherichia coli, Staphylococcus aureus, Salmonella typhimurium, proteus mirabilis, Shigella dysenteriae, hemolytic streptococcus, streptococcus pneumonia and Enterococcus faecalis, with the minimal inhibitory concentration0.1,0.05,0.1,0.2,0.8,1.6,1.6and0.05mg·mL-respectively.