Optimization of enzymic extraction by central composite design and study on antimicrobial activity of polyphenols in lentinus edodes

To explore the technology of extracting polyphenols from lentinus edodes, four single factors were studied including, extractive temperature, concentration of solvent, ratio of material to liquid, pectinase dosage. Based on the single factor tests, the optimum extraction technology was determined through center combination experiments and two degree polynomial regression analysis. The extractive temperature was 85℃, the ethanol concentration was 50%, the ratio of material to liquid was 1∶ 12, pectinase dosage was 1. 4%. Under this condition, polyphenols extraction rate was 2. 94%. After initinal purification of polyphenols, the bacteriostasis experiments were conducted using the agar plate dilution method. The results showed that the polyphenols from lentinus edodes had no antibacterial activity against fungi, but it had antibacterial activity against bacteria. In addition, the minimal inhibitory concentration for both Staphylococcus aureus and Escherichia coli were 15mg/mL.