发芽糙米多糖双水相萃取工艺优化及其抗氧化活性

以发芽糙米为原料,采用超声波辅助双水相法萃取对发芽糙米多糖的分配系数进行研究,多糖得率作为考察目标,通过正交试验确定超声波辅助双水相萃取发芽糙米多糖的最佳提取工艺条件。结果表明:发芽糙米多糖最优提取工艺为选用PEG6000、PEG6000添加量15.7%、硫酸铵添加量14.8%、萃取时间40min,该条件下多糖得率为81.07%。并采用DPPH法、邻苯三酚自氧化法和邻二氮菲法检测提取的多糖抗氧化活性。研究发现发芽糙米多糖对DPPH自由基、超氧阴离子自由基以及羟基自由基均有较强的抗氧化作用。

Extraction of polysaccharide from germinated brown rice by aqueous two-phase system and research of its antioxidant activity

The polysaccharide was extracted by the ultrasonic-assisted aqueous two-phase technology from germinated brown rice. The phase separation ability of different in PEG/(NH₄)₂SO₄ system was studied according to the polysaccharide yield. The yield of polysaccharide substance of germinated brown rice was determined by orthogonal experiment. The optimum process conditions were determined. Results were showed as follows: the mass fraction of PEG6000 was 15.7%, the mass fraction of ammonium sulfate was 14.8% and extraction time was 40 min. The yield of polysaccharide substance from germinated brown rice was 81.07% in the optimum conditions. Morever, the anti-oxidation of polysaccharide substance from germinated brown rice were studied by methods of DPPH, pyrogallol autoxidation and phenanthroline. The results showed that the polysaccharide of brown rice had stronger antioxidant effect to DPPH, ultra oxygen anion and hydroxyl radicals.