Studies On The Extraction Technology And Functions Of Shiitake Polyphenols

The Shiitake[Lentinus edodes(Berk)Singer]belongs to Basidiomycotina, Agaricomycotina, Agaricales, and Lentinus. It's a kind of precious fungus used for food and medicine. Shiitake, a keystone of the scientists' research in anti-cancer plants, some of its elements have rich medicinal value. Extraction technology, the anti-oxidantive effect and the antibacterial activity of Shiitake polyphenols were studied in this paper. Besides the active components of Shiitake polyphenols were analyzed by Shimadzu LC-20A HPLC. Therefore, an important recommendation for development and utilization of Shiitake polyphenols were offered.(1)The extraction technology of polyphenols from dried Shiitake was studied in this experiment. Different factors were considered, such as the concentration of solvent, extractive temperature, ratio of material to liquid, extraction time and extractive frequency. Based on the single factor tests, the optimum extraction technology was determined through orthogonal experiments: the ethanol concentration was 70%, the ratio of material to liquid was 1:20,the extraction time was 1.5 hours, the extractive temperature was 50℃. Besides the extractive possibility of Shiitake polyphenols through ultrasonic effect was studied. Thus the optimum extraction technology was determined: ethanol concentration was 90 %; the power of the microwave radiation was 80 W by 10 minutes.(2)The extraction and isolation conditions of Shiitake polyphenols were studied in this experiment. Factors about extraction pressure, extraction temperature, extraction capacity, and the amount of entrainer were investigated. And then based on the single-factor and orthogonal experimental tests, the best extraction technology were: 70% ethanol, extraction temperature 70℃, extraction pressure 35 MPa, CO₂ Current capacity 20L/h, the amount of entrainer 100mL, extraction time 1h, and the extraction rate of Shiitake polyphenols 2.03 mg/g. Under this condition, the higher extraction purity could reach.(3)Using the Vc as comparisons, the effect on scavenging·OH and·O₂^- of Shiitake polyphenols was studied by using fenton reaction and pyrogallol autoxidation methods respectively. The results showed that Shiitake polyphenols had certain ability to scavenge·OH and·O₂^- with the certain concentrations in the study. When the concentrations were same, Shiitake polyphenols had weaker ability to scavenge·O₂^- than Vc, but stronger ability than Vc to scaverge·OH under low concentrations. The oil anti-oxidation of Shiitake polyphenols was studied, In addition, the result shown that Shiitake polyphenols have certain ability of anti-oxidation to oil.(4)Compared with the effect of tea polyphenols, the antibacterial activity of Shiitake polyphenols was studied. The result shown that shiitake polyphenols have a notable inhibiting microorganism activity against Staphylococcus aureus, Escherichia coli, Bacillus subtilis and Salmonella typhimurium, but it have no antibacterial activity against Trichodenna viride and Stachybotrys Chartarum. Meanwhile, high temperature could certainly affect the antibacterial activity of Shiitake polyphenols, and the antibacterial effect of Shiitake polyphenols was not obviously changed in the pH6-8. In addition, the MIC for five kinds of bacterias were as follow: Staphylococcus aureus, 8mg/mL; Bacillus subtilis, 5 mg/mL; Escherichia coli, 4 mg/mL and Salmonella typhimurium, 9 mg/mL.(5)The determination of the components of Shiitake polyphenols was analyzed by Shimadzu LC-20A HPLC. The conditions of chromatography were: column temperature was 30℃, reversed-phase C18 chromatography column, run-time was 30min, flow rate was 1mL/min, detection wavelength was 310nm, mobile phase was adapted variable gradient with methanol-water solution. Thus the Shiitake polyphenols could be analyzed and the Chlorogenic acid could be separated on these conditions.