生物酶法制备白果微孔淀粉及其特性研究

Preparation and Characterization of Gingko Microporous Starch with Enzyme

以白果淀粉为原料,用生物酶降解的方法制备微孔淀粉,研究制备条件对白果淀粉成孔的影响。通过单因素和正交试验确定酶法制备白果微孔淀粉的最优工艺条件为:20 g白果淀粉,酶种类为α-淀粉酶,酶用量2.0%,pH值5.5,酶解温度40℃,酶解时间18 h,白果微孔淀粉的得率为92.5%,吸水率由102%提高到162%。采用扫描电子显微镜(SEM)和差示扫描量热仪(DSC)对白果微孔淀粉的颗粒结构和热特性进行分析,并将其与原白果淀粉进行比较。结果表明,制备的白果微孔淀粉表面有凹坑或孔洞,内部有空腔,其糊化温度范围(温差7.69℃)较原淀粉变窄(温差8.27℃),焓变值为1.913 J/g,较原淀粉无明显变化。

Gingko microporous starch was prepared by enzymatic hydrolysis treating with gingko starch as raw material. The effect of enzyme species, quantity of enzyme, pH value, temperature and time on pores formation was investigated. The optimal conditions for the microporous starch production obtained by single factor and orthogonal experiments are as follows： enzyme type of α-amylase, quantity of enzyme 2% , pH value 5.5, reaction temperature 40 ℃ and reaction time 18 h. The granule structure of the gingko porous starch was observed with SEM, and heat properties were analyzed with DSC. It was compared with raw gingko starch, as well. The results show that there are holes on the surface of gingko microporous starch granules, with cavities Within the holes, the gelatinization temperature range Of the gingko microporous starch is narrowed, and the endothermic enthalpy is not changed evidently.