毛葱水溶性多糖的超声波微波协同法提取工艺优化及结构分析

以毛葱为原料,利用超声波微波协同法提取毛葱水溶性多糖。以多糖得率为考察指标,在单因素试验的基础上,通过响应面分析方法确定毛葱水溶性多糖提取的最佳工艺为液料比17∶1(mL/g)、超声波功率360 W、微波功率200 W、协同时间16 min,此条件下毛葱水溶性多糖得率为(11.92±0.13)%。溶解性实验结果表明:该毛葱水溶性多糖可溶于水,不溶于有机溶剂;显色反应实验结果表明:该毛葱水溶性多糖含有糖醛酸,但不含淀粉及酚类物质。紫外光谱分析显示该毛葱水溶性多糖无明显的核酸和蛋白质的特征吸收峰,傅里叶变换红外光谱分析显示该毛葱水溶性多糖具有多糖类的特征吸收峰。高效凝胶渗透色谱法分析该毛葱水溶性多糖的重均分子质量,可初步得出该毛葱水溶性多糖不是由均一组分构成的。

Optimization of Ultrasonic Microwave-Assisted Extraction and Structural Analysis of Water-Soluble Polysaccharide from Tillering Onion

This paper reports the optimization of the ultrasonic microwave-assisted extraction of water-soluble polysaccharides from tillering onion by one-factor-at-a-time method and response surface methodology. The response was polysaccharide yield. The optimum conditions were determined as follows: liquid-to-solid ratio, 17:1 (mL/g); ultrasonic power, 360 W; microwave power, 200 W; and irradiation time, 16 min. Under the optimized conditions, the polysaccharide yield was (11.92 ± 0.13)%. Solubility results showed that the extracted polysaccharide was soluble in water but insoluble in organic solvents. The results of color reaction experiments showed that the water-soluble polysaccharide did not contain starch or phenolic compounds but contained uronic acid. As indicated by ultraviolet-visible spectroscopy measurement, the water-soluble polysaccharide had no characteristic absorption peaks of nucleic acid and protein. Fourier transform infrared spectroscopy showed that the water-soluble polysaccharide had the characteristic absorption peak of polysaccharide. The weight average molecular weight was analyzed by high performance gel permeation chromatography. It was found that the water-soluble polysaccharide was not composed of homogeneous components.