微波辅助提取澳洲坚果壳多糖的工艺优化及抗氧化性评价

Optimization of Microwave-Assisted Extraction of Polysaccharides from Macadamia integrifolia Shell and Evaluation of Their Antioxidant Activities

优化微波辅助提取澳洲坚果壳多糖的提取工艺,并测定其多糖的抗氧化性。在单因素试验的基础上,以多糖提取率为指标,通过L_9(3~3)正交试验优化其多糖的提取工艺参数,并通过澳洲坚果壳多糖对·OH、1,1-苯基-2-苦肼基(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基和O_2^-·的清除来评价其抗氧化能力。结果表明,最佳提取工艺参数为微波功率200 W、微波时间2.5 min、料液比1:50(g/mL),在该条件下多糖的平均提取率为0.70%;多糖质量浓度为0.027 5 mg/mL时,对·OH、DPPH自由基和O_2^-·的清除率可分别达到63.11%、61.90%和80.09%,说明提取的澳洲坚果壳多糖对·OH、DPPH自由基和O_2^-·有较好的清除能力。

In this study, the microwave-assisted extraction of polysaccharides from Macadamia integrifolia shell was optimized, and the antioxidant properties of the extracted polysaccharides were determined. Optimization of extraction parameters for improved extraction efficiency of polysaccharides was done using single factor experiment and an orthogonal array design L9（3^3）. Meanwhile, the antioxidant activities were evaluated by hydroxyl, 1,1-diphenyl-2-picrylhydrazyl（DPPH） and superoxide anion free radical scavenging assays. The optimum extraction parameters were determined as follows： microwave power, 200 W; microwave irradiation time, 2.5 min; and solid-to-solvent ratio, 1：50（g/mL）. Under these conditions, the average extraction yield of polysaccharides was 0.70%. At a polysaccharide concentration of 0.027 5 mg/mL, the percentage scavenging of ·OH, DPPH free radical and O2^-· were 63.11%, 61.90% and 80.09%, respectively, implying that these polysaccharides have good ability to scavenge ·OH, DPPH free radical and O2^-·.