野生薯蓣膳食纤维的提取及对自由基的清除作用

Extraction of dietary fiber from yam and its ability of remove free radicals

以薯蓣粉为材料,设计4因素3水平的正交试验,酶法提取膳食纤维。结果表明:0.7%混合酶(α-淀粉酶与糖化酶质量比为6∶1),处理温度60℃,处理时间80 min,0.5%蛋白酶在60℃处理60 min,对淀粉和蛋白质的脱除较彻底。以体外试验研究不同质量浓度(20～140 mg/mL)的膳食纤维鲜样和可溶性淀粉对自由基的清除效果,设计3种不同的反应体系:1,1-二苯基-2-苦味肼基自由基(DPPH)、超氧阴离子自由基(O2.)、羟自由基(.OH)。结果表明:薯蓣膳食纤维对3种自由基都有一定的清除能力,平均消除率分别为53.23%、31.67%、30.38%。对3种自由基清除能力大小顺序为:DPPH自由基>超氧阴离子自由基>羟自由基。另外,可溶性淀粉对3种自由基也有轻微的清除能力,其平均清除率分别为2.81%、6.98%、6.48%。

The dietary fiber was extracted from yam by enzymatic hydrolysis and tested by orthogonal ex- periment. The results indicated that the optimal extraction processing conditions were, 0.7% mixed en- zyme （ α - amylase and glucoamylase at the ratio of 6：1 ）, hydrolysis temperature 60 ℃ and hydrolysis time 80 min, 0.5 % protease at 60 ℃ for 60 rain. The scavenging effects of fresh dietary fiber and solu- ble starch with various concentrations （20 -140 mg/mL） on DPPH, superoxide anion and hydroxyl free radicals were also investigated in vitro. Results exhibited that the dietary fiber had strong scavenging ca- pability on the 3 kinds of free radicals. The average scavenging rates of dietary fiber from yam on DPPH, superoxide anion and hydroxyl free radicals were 53.23% ,31.67% and 30.38%, respectively. In addi- tion, soluble starch had mild scavenging faction on the 3 kinds of free radicals. The average scavenging rates were 2.81% ,6.98% and 6.48%, respectively.