挤压处理提高玉米麸皮水溶性多糖含量及其抗氧化活性研究
Improving effect on the yield of corn fiber soluble polysaccharides by extrusion and evaluation of antioxidant activity
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摘要: 以玉米麸皮为原料,对其进行双螺杆挤压改性处理,以提高玉米皮水溶性多糖含量。以改性后可溶性多糖得率为指标,采用单因素及正交实验对挤出的温度、螺杆转速及加水量进行优化;采用邻二氮菲-Fe2+氧化法、邻苯三酚自氧化法及比色法研究玉米皮可溶性多糖对羟基自由基、超氧阴离子及DPPH自由基的清除作用及还原能力。结果表明,最佳挤出条件为:螺杆转速150r/min,加水量20%,熔体温度140℃。该条件下玉米皮所得多糖得率达24.91%,是未挤压前的2.7倍,所得粗多糖纯度有所提升,分子量减小。经挤压改性后玉米皮多糖清除羟自由基、超氧阴离子自由基、DPPH自由基及还原能力均有不同程度提高。Abstract: Corn fiber was modified by twin- screw extrusion technology.The extruded melt temperature, water addition and rotary speed of screw were optimized through single factor and orthogonal experiment according to the yield of soluble polysaccharides.The reducing power and scavenging effects of corn fiber soluble polysaccharides on the hydroxy free radical, superoxide anion radical and DPPH · were determined by Phenanthroline-Fe2 +method, pyrogallol autoxidation method and colorimetric methods.The results showed that the optimum conditions were as follows, rotary speed of screw 150r /min, the melt temperature 140℃ and the water addition 20%.Under this condition, the yield of soluble polysaccharides was 2.7 times higher than before, reached to 24.91%.The purity of crude polysaccharides had improved and the molecular weight had been decreased.The reducing power and scavenging effects of treated soluble polysaccharides on the hydroxy free radical, superoxide anion radical and DPPH·were improved greatly compared with untreated ones.
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