富硒黑木耳硒多糖超声–微波提取工艺优化及其抗氧化活性

以富硒黑木耳中的硒多糖为考察指标,采用超声–微波提取法,分别设超声时间、微波时间、超声功率、微波功率、料液比5个单因素试验,再选择对富硒黑木耳中硒多糖提取率有显著影响的4个因素(超声时间、微波时间、微波功率和料液比)进行响应面分析,优化富硒黑木耳硒多糖的提取工艺条件。结果表明:采用超声–微波提取富硒黑木耳中硒多糖,在超声时间26 min、微波时间22 min、微波功率350 W以及料液比1∶58(g/m L)时,硒多糖提取率最高,为11.79%,与传统水提法相比,提高了4.1%,提取时间缩短了56.67%。以传统水提法提取的富硒黑木耳中硒多糖为对照,进一步研究超声–微波提取富硒黑木耳中硒多糖的总还原力以及对羟基自由基和DPPH自由基的清除率,结果表明,超声–微波提取的富硒黑木耳硒多糖和传统水提法提取的硒多糖的还原力吸光值分别为0.431和0.410,对羟基自由基清除的半抑制浓度(IC50)值分别为3.81、4.91 mg/m L,对DPPH自由基清除的IC50值分别为4.59、5.70 mg/m L,说明超声–微波提取的富硒黑木耳硒多糖抗氧化活性优于传统水提法提取的硒多糖。

Process optimization on extracting of selenium polysaccharides with ultrasonic and microwave method from selenium-enriched Auricularia auricula and its antioxidant activity

Selenium polysaccharides extracting from selenium-enriched Auricularia auricula by the ultrasonic and microwave method was used as an index in this test. The effects of different ultrasonic time, microwave time, ultrasonic power, microwave power and ratio of liquor to material on extracting rate of selenium polysaccharides were investigated by single factor experiment, then ultrasonic time, microwave time, microwave power and ratio of liquor to material, the four factors which had significant effects on extraction rate of selenium polysaccharides were chosen to determine the optimum process parameters in response surface test. The results showed that under the conditions of 1∶58 (g/mL) of ratio of liquor to material, 26 min of ultrasonic time, 22 min of microwave time and 350 W of microwave power, the selenium polysaccharides extraction rate and the extraction time were the highest (11.79%) and shortest, which were 4.1% higher and 56.67% shorter than those by the water-extractable method. The results from the antioxidant tests in vitro with different selenium polysaccharides showed that absorbance values of reducing capacity, the IC50 values of scavenging against hydroxyl free radical and the IC50 values of scavenging against DPPH free radical of selenium polysaccharides by the ultrasonic and microwave method and the water-extractable method were 0.431 and 0.410, 3.81 and 4.91 mg/mL, and 4.59 and 5.70 mg/mL, respectively .The antioxidant activity of selenium polysaccharides extracted by ultrasonic and microwave method was better than that of selenium polysaccharides extracted by the water-extractable method.