在碱提法提取凉粉草胶的基础上,探讨超声对凉粉草胶的辅助提取作用,并比较了不同提取方式对凉粉草胶的胶体性质和化学组成的差异。结果显示:采用超声辅助提取30min,温度100℃,Na2CO3浓度为4mg/mL,料液比为1∶20(g∶mL),提取功率为400W的条件下,凉粉草胶粗胶提取率由碱提法的29%提高到33%,提取时间从1.5h缩短为30min。超声辅助提取的粗胶形成的胶体凝胶强度更大,可能的原因是其中的多糖分子破坏较小,分子较大。同时,其中的钙、钾元素的存在也对其凝胶性质有一定的影响。

The effect of ultrasound on extract of Mesona blumes Gum and the difference of gel property and chemical composition of different extracted methods were discussed. The results showed that gum yields increased from 29% to 33% and extract time shorten from 1.5 h to 30 min with ultrasonic-assisted extracting method. The optimum extracting time was 30min,and the extract temperature was 100℃,the concentration of alkali was 0.4%,the ratio of solid to liquid was 1:20,and the ultrasonic power was 400 W. The gel strength of mixed gel of ultrasonic-assisted extract and starch was much better than that of mixed gel of alkaline extract and starch. This may due to the large molecular size of polysaccharide of Mesona blumes without any damage. Besides,the calcium and kalium also affected the property of mixed gel.