超声协同酶法提取紫花苜蓿多酚及其抗氧化性质

Ultrasonic-enzyme synergistic extraction and antioxidant activity analysis of alfalfa polyphenols

采用超声协同酶法提取紫花苜蓿多酚。以多酚提取量为指标,考察了液料比、加酶量、酶解时间、超声时间、超声温度及pH 6个因素对多酚提取效果的影响,并通过响应面法优化该提取工艺。同时探讨其抗氧化活性。结果表明,超声协同酶法提取紫花苜蓿多酚的最佳工艺条件为酶量4.9%、超声时间74 min、超声温度49℃,多酚提取量可达3.642mg·g^(-1)。此外,紫花苜蓿多酚具有较好的抗氧化活性,其清除DPPH和·OH自由基的半数抑制浓度IC50分别为10.78和19.28μg·mL^(-1)。

The polyphenols from alfalfa were extracted by ultrasonic-enzyme synergistic method.The effects of liquid-solid ratio,enzyme addition volume,enzyme incubation time,ultrasonic time,ultrasonic temperature and pH on phenol yield of alfalfa were investigated,and the extraction technology was optimized by response surface experiment.The antioxidant activities of alfalfa phenols were also studied.The results showed that the optimum technology factors for extracting alfalfa phenols were as follows：enzyme addition was 4.9%,ultrasonic time was 74 min and ultrasonic temperature was 49℃.Under this condition,the highest extraction quantity of total phenols could reach 3.642 mg·g^（-1）.In addition,the phenols showed strong activities for DPPH（2,2-diphenyl^（-1）-picrylhydrazyl）and hydroxyl radical scavenging,and the half scavenging concentration（IC50）of DPPH and ·OH radicals were 10.78μg·mL^（-1） and 19.28μg·mL^（-1）,respectively.