干热变性莲子淀粉特性的研究

从淀粉的颗粒特性、淀粉糊特性及淀粉糊化后的成膜特性等方面对干热变性莲子淀粉特性进行系统的研究，以期为干热变性莲子淀粉的进一步研究开发利用提供理论基础。结果表明：添加海藻酸钠对莲子淀粉干热处理后，淀粉颗粒多数呈椭圆形，少部分淀粉颗粒表面有细微裂纹，颗粒彼此粘连，淀粉颗粒表面有粘连物；溶解度升高，膨胀度降低，淀粉糊透明度降低。干热变性处理对提高莲子淀粉糊冻融稳定性的作用不明显；布拉班德黏度曲线显示，添加海藻酸钠进行干热变性后莲子淀粉起糊温度明显降低，终值黏度降低，热稳定性降低，冷稳定性增强，凝沉性减弱。添加海藻酸钠进行干热变性可以提高莲子淀粉膜的机械性能和阻水性，降低膜的溶解度。

The Characteristics of Lotus Seed Starch Modified by Dry Heating

The characteristics of granule, pastes and film-forming after gelatinization of lotus-seed starch modified by dry heating were systematically studied in order to provide a theoretical basis for further exploitation and utilization of dry-heating modified lotus-seed starch. The results showed that the lotus-seed starch granule was modified by dry heating with alginate elliptic shape mostly, few of them had slight crack on the surface, adhesive matters could be found on the surface of starch particles which adhesion to each other. Modified lotus seed starch had higer solubility, lower swelling power and the transparency of modified starch pastes was lower. The effect of dry heating on the freeze-thaw stability of lotus seed starch pastes is not clear. According to Brabender viscosity curve, the lotus-seed starch modifed by dry heating with alginate had a lower beginning gelatinization temperature and peak viscosity, weaker thermostability, stronger cold viscosity stability and weaker retrogradation. Dry heating with sodium alginate could increase mechanical property, improve water vapor barrier property and decrease the solubility of modified lotus seed starch based films.