复合酶协同超声提取藜麦皂苷及其抗氧化性

Optimization of saponins extraction from quinoa husk using ultrasonic-complex enzyme assisted and its antioxidant activities

摘要:

采用复合酶协同超声提取藜麦种皮皂苷，并对其抗氧化活性进行了测定。以藜麦皂苷的提取率为指标，考察了酶配比〔m（纤维素酶）：m（果胶酶）〕、酶用量、酶解温度、pH、酶解时间对藜麦皂苷提取率的影响，并用响应面法进行了优化。得到最佳工艺条件为：总酶用量(以藜麦种皮质量为基准)为1.5%，酶配比〔m（纤维素酶）：m（果胶酶）〕为3∶2，酶解温度为50.5℃，pH为5.5，酶解时间为0.25 h；在该条件下，藜麦皂苷的提取率较高，达到85.32%；该法对藜麦种皮皂苷的提取率比单一纤维素酶提取率(81.56%)高4.41%，比单一果胶酶提取率(82.20%)高3.66%，比单独超声提取率高16.76%。采用清除1,1-二苯基-2-三硝基苯肼自由基(DPPH•)的能力，分析藜麦皂苷的抗氧化活性，结果表明，藜麦皂苷具有显著的抗氧化活性，且与皂苷的质量浓度呈剂量依赖性。

Abstract:

The technology of saponins extracting from quinoa husk using ultrasonic-complex enzyme assisted and its antioxidant activities have been established in this research. Taking the extraction rate of quinoa saponins as the index, the effects of four operational factors, that is, the ratio of cellulose and pectinase, temperature, pH value and hydrolysis time have been studied by single factor experiments. On the basis of the single factor experiments, the extraction technology of saponins from quinoa husk using complex enzyme synergistic ultrasound was optimized by response surface methodology. The optimum conditions were as follows: total enzyme dosage ( the quality of saponins as the base）was 1.5%, enzyme ratio〔m（cellulase）：m（pectinase）〕 was 3∶2, enzymatic hydrolysis temperature was 50.5 °C, pH was 5.5, and enzymatic hydrolysis time was 0.25 h. Under optimal conditions, extraction rate of quinoa saponins was highest and reached 85.32%. The extraction rate using ultrasonic-complex enzyme assisted was 4.41% higher than only cellulase (81.56%), 3.66% higher than only pectinase (82.20%), and 16.76 higher than only ultrasonic extraction. The antioxidant activities of the extracted saponins was evaluated by DPPH•. The results show that the saponins obtained from quinoa husk had antioxidant activities. saponins' concentrations and antioxidant activity were in a dose- dependent manner.