醋酸酯化对机械活化玉米淀粉微生物降解性能的影响

Effects of actiyl esterification on the biodegradability of mechanical activated maize starch

利用微生物群在半生物体内模型中,以降解速度与降解程度为评价指标,研究机械活化玉米醋酸酯淀粉的微生物降解性能。结果表明,醋酸酯化对机械活化淀粉的微生物性能有很大的影响,明显促进了降解速度和降解程度。取代度为0·06的机械活化玉米醋酸酯降解5d的速度为59·53mg·g-1·d-1,淀粉的残余质量分数为3·48%;而未经酯化的机械活化玉米淀粉的微生物降解速度仅为38·99mg·g-1·d-1,淀粉的残余质量分数为15·40%。随着取代度的提高,微生物降解速度加快,降解程度提高,并利用扫描电子显微镜对部分降解的淀粉样品的颗粒形貌进行了观察。

Using biodegradation rate and degree as evaluating parameter,the biodegradability of maize acetate starch from mechanical activation was investigated in a half-vivo model by using micropopulation symbiotic co-cultures.The results indicated that acetyl esterification had great influence on biodegradability,the biodegradation rate sped up and the biodegradation degree increased as well.For maize acetate starch with a degree of substitution（DS）of 0.06 from mechanical activation,the biodegradation rate was 59.53mg·g-1·d-1 and the residual starch mass was 3.48% after 5 days,the biodegradation rate of mechanical activated maize starch was only 38.99mg·g-1·d-1 and the residual starch mass was 15.40%.The biodegradation rate and degree were increased as the degree of substitution（DS）increased.The morphology of maize starch and mechanical activated maize starch and maize acetate starch granules degraded partially were investigated by scanning electron microscope（SEM）.