响应面优化西兰花茎硫苷提取及其抗氧化性研究

Optimization of Extraction by Response Surface Methodology and Antioxidant Activity of Glucosinolates from Broccoli Stems

以西兰花茎为原材料,采用超声辅助提取西兰花茎的硫苷,研究了超声功率、超声时间、提取温度、磷酸盐缓冲液(phosphate buffered saline,PBS)浓度和料液比对硫苷含量的影响,在单因素基础上采用Box-Benhnken中心组合法进行四因素三水平试验设计,以硫苷含量为响应值,进行响应面分析;并初步探究西兰花茎硫苷的抗氧化能力。结果显示,最佳工艺组合为,超声功率80 W、超声时间22 min、提取温度40℃、料液比1∶16(g/mL),在此工艺条件下提取的硫苷含量为0.732 mg/mL,与理论值相对误差为1.1%,说明试验结果符合该模型。以市售苹果汁为载体,添加提取原液和冻干物两种形式的西兰花茎提取物,抗氧化值有显著提高(p<0.05),抗氧化能力由原来的4.08μmol Trolox/mL分别提高到6.65μmol Trolox/mL和9.16μmol Trolox/mL,平均提升了2倍～3倍。

Taking broccoli stems as raw material,glucosinolates(GS)of broccoli stems were extracted by the method of ultrasonic-assisted,and the ultrasonic treatment power,ultrasonic treatment time,extraction temperature,phosphate buffered saline(PBS)buffer concentration,solid-liquid ratio were invested.Based on the single factor tests,Box-Benhnken center composite experiment was carried out with four factors three levels to perform response surface analysis which put the extraction volume of GS as the response values,and the antioxidant activity of the GS was preliminarily explored.The results showed that,the optimal conditions were as follows:ultrasonic power was 80 W,ultrasonic treatment time was 22 min,extraction temperature was 40℃,and solid-liquid ratio was 1∶16(g/mL).Under this condition,the extraction volume of GS was 0.732 mg/mL,which was close to the measured value.The relative error between the actual values and predicted values was only 1.1%.Extracts and lyophilizate of broccoli stems were added to the commercial apple juice,the antioxidant value increased significantly(p<0.05),form 4.08μmol Trolox/mL to 6.65μmol Trolox/mL and 9.16μmol Trolox/mL respectively.The average antioxidant activity was increased of 2-3 times.