[关键词]
[摘要]
本文分别制备水相戊二酸木薯淀粉酯(AGAC)和醇相戊二酸木薯淀粉酯(EGAC),使用FT-IR、XRD和SEM进行微观表征,研究两种酯化淀粉的粘度、透明度、流变性、冻融稳定性和抗盐性等理化性质。微观表征的结果显示两种酯化淀粉分子中成功接入了戊二酸基团,两者的晶型均没有发生变化,其整体结构没有受到很大影响,布拉班德粘度仪分析结果表明AGAC的峰值粘度有所提高,同时糊化温度明显降低,EGAC的糊化温度降低,峰值粘度大幅度提高,但粘度稳定性没有提高。AGAC糊液和EGAC糊液的透明度、冻融稳定性和抗剪切力均强于原淀粉,而AGAC和EGAC抗盐性均低于原淀粉,即其热糊稳定性和抗盐性未得到改善。EGAC的透明度高于原淀粉,但低于AGAC;而冻融稳定性、抗剪切能力均略优于AGAC和原木薯淀粉,引入戊二酸基团后,木薯淀粉的透明度、冻融稳定性和抗剪切能力有一定程度的提高。
[Key word]
[Abstract]
In this paper, aqueous glutarate acid cassava starch esters (AGAC) and ethanolic glutarate acid cassava starch esters (EGAC) were prepared and characterized by FTIR, XRD and SEM. The viscosity, transparency, rheological properties, freeze-thaw stability, salt resistance and other physicochemical properties of AGAC and EGAC were studied. The results of microscopic characterization showed that the glutaric acid groups were successfully incorporated into the two esterified starch molecules, with their crystal structures remaining unchanged and the overall structure not greatly affected. Analysis with the Brabender viscometer revealed that the peak viscosity of AGAC increased, while the gelatinization temperature is significantly lowered. The gelatinization temperature of EGAC decreased along with greatly increased peak viscosity , although the viscosity stability was not improved. The transparency, freeze-thaw stability and shear resistance of AGAC paste and EGAC paste were greater than those of the original starch, with AGAC and EGAC having lower salt resistance than the original starch, that is, their thermal paste stability and salt resistance had not been improved. EGAC had greater transparency than the original starch but smaller than AGAC, with the freeze-thaw stability and shear resistance slightly better than that of AGAC and original cassava starch. After the introduction of glutaric acid group, the transparency, freeze-thaw stability, stability and shear resistance of cassava starch have been improved to some extent.
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[基金项目]
广州市对外科技合作项目(201508030020)