Optimisation of Enzyme-Assisted Ultrasonic Extraction of Total Polyphenols from <i>Rhododendron </i><i>tomentosum</i> Harmaja and Hypoglycaemic Activities

本文以杜香为原料，采用酶辅助超声法提取杜香总多酚。在单因素实验基础上，选择加酶量、超声功率、乙醇体积分数三个因素进行Box-Behnken响应面优化实验，以杜香总多酚得率为响应值，确定杜香多酚的最佳提取工艺，并对提取的杜香多酚进行降糖降脂的活性研究。结果表明：在加酶量为3%、超声功率300 W、乙醇体积分数为45%时，杜香总多酚得率达70.19 ± 0.31 mg/g，与预测值71.66 ± 0.19 mg/g 高度吻合。当多酚浓度为5 mg/mL时，对α-淀粉酶和α-葡萄糖苷酶的抑制率分别可达到80.1%和85.6%。这说明杜香多酚具有较好的降血糖生物活性，该研究可为杜香多酚后续的研究开发提供理论依据。In this study, the total polyphenols were extracted by enzyme-assisted ultrasonography from the Rhododendron tomentosum Harmaja. On the basis of single factor experiments, the Box-Behnken response surface optimization experiment was carried out by selecting three factors: enzyme amount, ultrasonic power and ethanol volume fraction. The optimal extraction process was determined by taking the yield of total polyphenols as response value. The antioxidant and hypoglycemic activities of the extracted polyphenols were studied. The results showed that under the conditions of 3% enzyme dosage, 300 W ultrasonic power and 45% ethanol volume fraction, the yield of total polyphenols reached 70.19 ± 0.31 mg/g, which was highly consistent with the predicted value of 71.66 ± 0.19 mg/g. When the polyphenol concentration was increased to 5 mg/mL, the inhibition rates of α-amylase and α-glucosidase reached 80.1% and 85.6%, respectively. This suggests that polyphenols have better hypoglycemic biological activities. This study can provide a theoretical basis for the subsequent research and development of polyphenols.