颗粒冷水可溶高直链玉米淀粉的制备及特性研究

以高直链玉米淀粉为原料,采用乙醇-碱法和羟丙基醚化法结合,研究不同碱添加量、环氧丙烷添加量、反应时间、反应温度下淀粉的冷水溶解度和羟丙基含量的变化规律。结果发现:随碱添加量的增加,淀粉颗粒的溶解度先上升后降低,羟丙基含量随碱添加量的增加而增加;随环氧丙烷添加量的增加,溶解度呈现先升高后降低的趋势,羟丙基含量随环氧丙烷添加量的增加出现先升高后降低的趋势;随反应时间的延长,溶解度先升高后略有降低,羟丙基含量随反应时间的增加而增加;随反应温度的增加,溶解度先升高再降低,羟丙基含量随温度的升高先增加后略有下降。对制得的不同溶解度下颗粒冷水可溶淀粉糊的透明度研究发现,随着淀粉溶解度的增大,淀粉糊透明度显著提高。扫描电镜观察冷水可溶淀粉的颗粒形态保持完整,但表面出现凹陷。X射线衍射结果显示:冷水可溶淀粉颗粒的晶型从高直链淀粉的"B"型结晶变为"V"型,且尖峰衍射峰消失,全部变为弥散特征峰。

Study on Preparation and Properties of Granular Cold Water Soluble High Amylose Maize Starches

This paper is to select high amylose maize starch as the raw material,combine the alcoholic-alkaline treatment and hydroxypropyl etherification method.The change rules of solubility and hydroxypropyl content at different dosage of sodium hydroxide,epoxy propane addition amount,reaction time and reaction temperature were investigated.The results showed that,with the increase of alkali addition,the solubility of starch granules increased first and then decreased,and the hydroxypropyl content increased;with the increase of epoxy propane,the solubility increased first and then decreased,and the hydroxypropyl content increased first and then decreased.With the expand of reaction time,the solubility increased first and then decreased slightly,and the hydroxypropyl content increased.With the increase of reaction temperature,the solubility increases first and then decreases,and the content of hydroxypropyl increases first and then decreases slightly.The transparency of the starch paste was remarkably improved as the solubility increased.The particle shape of the cold water soluble starch (GCWSS) remained intact,but it appeared concave on the surface.The results of XRD showed that the crystal form of the starch granule was changed from the "B" type crystal of the high amylose starch to the "V" type,and the sharp diffraction peaks were disappeared and all became diffuse characteristic peaks.