凤丹牡丹多酚提取及其抗氧化活性研究

Determination of in vitro antibacterial activity of antioxidant and the extraction of Fengdan peony polyphenols

为提高凤丹牡丹(Paeonia suffruticosa Fengdan)叶的多酚提取率,采用纤维素酶法提取叶中的多酚,以多酚提取量为考察指标,在单因素试验的基础上,选取纤维素酶用量、酶解温度、酶解时间、pH 4个因变量,进行响应面试验,建立各因变量与响应值之间的数学模型,确定最佳提取工艺条件。结果表明,曲面回归方程拟合性良好,其中纤维素酶用量和酶解温度的交互作用显著,得到多酚的最优工艺条件为纤维素酶用量150 U/mL、pH 5.0、酶解温度50℃、酶解时间105 min,在此条件下,多酚提取量达到34.66 mg/g,与模型预测值35.10 mg/g接近。凤丹叶片提取液对DPPH·清除率在提取液浓度为0.06 mg/mL时达到82.15%;对·OH清除率在提取液浓度为0.32 mg/mL时达到27.10%;铁氰化钾还原力在提取液浓度为10 mg/mL时,吸光度为3.41。

In order to improve the comprehensive utilization rate of peony(Paeonia suffruticosa Fengdan) leaf of Fengdan resources, the polyphenols in the leaves of peony were extracted by cellulase method, and the polyphenols were used as the index. The effects of cellulase concentration, enzymatic hydrolysis temperature, enzymatic hydrolysis time and pH value on the extraction of polyphenols in peony leaves were investigated by response surface. The results showed that the best condition for extraction of polyphenols from peony leaves by cellulase was: when the concentration of cellulase was 150 U/mL, the pH was 5.0, the enzymatic time was 105 min, the temperature of enzymatic hydrolysis was 50 ℃. Under this condition, the theoretical prediction value of polyphenol content was 34.66 mg/g. The antioxidant activity of the best condition for extraction was examined. The DPPH· scavenging abilities of Fengdan leaf extract reached 82.15% when the extract concentration was 0.06 mg/mL;the hydroxyl scavenging abilities reached 27.10% when the concentration was 0.32 mg/mL;reducing abilities of the potassium ferricyanide absorbance was 3.41, when the concentration of the extract was 10 mg/mL.