介质阻挡放电等离子体与淀粉溶液的反应

Reaction of dielectric barrier discharge plasma with starch solution

采用大气压氦气介质阻挡放电等离子体处理淀粉溶液。利用扫描电子显微镜观察淀粉的形貌,发现经等离子体处理后淀粉颗粒体积变小,并且更容易聚集。标准pH计检测发现,淀粉溶液pH值随着等离子体处理时间的延长呈现大幅度的下降,等离子体处理后立即检测和2 h后检测的结果基本相同。采用高效液相色谱分析经等离子体处理过的淀粉溶液,发现主要产物中含有葡萄糖和乙酸。比较传统淀粉酸水解和等离子体水解结果可见,后者水解程度明显大于前者,说明等离子体中活性成分与淀粉溶液发生化学反应,解离淀粉长链是其水解的主要原因。等离子体与淀粉溶液反应产生的酸对淀粉水解的贡献很小。

A starch solution sample was exposed in dielectric barrier discharge （DBD） plasma in helium at atmospheric pressure without any additional inorganic acid or enzymes. The micrography of a scanning electron microscope showed that starch particle became small and was easy to aggregate. The pH value of the solution was observed by a standard pH meter. With the plasma treatment time extension, the pH value of solution decreased sharply. The pH value was almost same on mater when the sample was analyzed immediately or 2 hours later after plasma exposure. The high performance liquid chromatograph （I-LPLC） shows that the final hydrolysis products include glucose and acetic acid. Compared the degree of starch hydrolyzed by acid and plasma, the latter is more remarkable. The results indicate that the reactive radicals in plasma reacted with the starch and broke the bioacromolecule, which played a very important role on starch hydrolysis, but the high acid induced by plasma contributed little.