| Plant polyphenols are widely present in plants of the fruit, skin, meat, shell, as the unique biological activity, become a research hotspot. Now, as well known the Plant polyphenols has been widely used in the food, medicines, health products and cosmetics and other fields, as a natural antioxidant or antimicrobial. The plant polyphenols has many kinds and complex structure, so hard synthesized that must be extracted from the natural substance. In order to make full use of acorn resources, polyphenols was extracted from Acorn shuck. In this paper, we studied the the optimum extracting method and conditions of acorn shuck polyphenols and purified with the macroporous resin. We also analysed polyphenols extraction by high performance liquid chromatography. Acorn shells polyphenols was studied in antioxidant and antibacterial activity that made a preliminary determination at last. The main results were shown as follows:Methods of organic solvent extraction and supersonic wave assisted extraction method were used to extract polyphenols from acorn shells and the optimum extraction conditions were shown as follows:the optimum extracting condition for organic solvent extraction method was as follows:60%acetone as extracting solvent with a sofid/solvent ratio of 1:30extracting for 80 min at 50℃. Under this condition, the extracting yield was 9.66%; for ultrasonlc-assisted extraction method, the optimum condition was as follows: 60% acetone as extracting solvent with a solid/solvent ratio of 1:29, extracting for 17.4 min in the ultrasonic power of 325.6W. Under this condition, the extracting yield Was 12.31%. Compared with acetone extraction and ultrasonic extraction methods, ultrasonic extraction has the advantages of faster extraction, lower energy consumption and high extraction yield.Through static adsorption and desorption experiments, it was showed that the crude extract could be better separated and purified by number AB-8 macro porous resin. The optimum adsorption and separation conditions for the crude extract on number AB-8 macrodomes resin were confirmed as follows: the pH=4, feed concentration of 4mg/ml with flow rate of 2BV/h; the desorption solvent was 2BV of 60% ethanol with flow rate of 2BV/h. The highest purity was 80.8% of acorn shuck polyphenols.The high performance liquid chromatography (HPLC) on acorns shell polyphenols component analyzed results shown that it includes phenolic acid and tannins, the probable flavonols compound. All that could be provide theoretical foundation of further application for acorns shell polyphenols.The antioxidant and antibacterial results of Acorn shell polyphenol suggest that: Acorn shell polyphenol scavenging of superoxide anion was similar to scavenging of hydroxyl radical and was higher of BHT antioxidant activity, slightly lower than Vc. The lower concentration of acorn shell polyphenol reducing power was stronger than BHT and Vc. Overall, acorn shell has a higher polyphenol than BHT antioxidant.The antibacterial effects of acorn shell polyphenol were studied on the antibacterial effects to four bacteria such as Escherichia coli, Staphylococcus aureus, Mucor, Aspergillus niger, Cerevisiae Saccharomyces and Yeast, results showed that all have got to be inhibited. But the antibacterial effect is different to kinds of the strain of acorn shell polyphenol extracts, to E. coli and Staphylococcus aureus have a strong inhibitory effect, while to Aspergillus niger, and Mucor have some weak inhibitory effect, to normal yeast and Saccharomyces cerevisiae have not significant inhibitory effect. Compared with sodium benzoate, the results showed that acorn shells polyphenols's inhibitory effect is stronger. |
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