淀粉纳米颗粒在不同增塑剂中的糊化与流变特性研究

本文以蜡质玉米淀粉为原料，经普鲁兰酶酶解脱支，短直链淀粉重结晶制取淀粉纳米颗粒(SNPs)。采用差示扫描量热仪（DSC）和动态流变仪，探究了不同浓度SNPs在甘油、山梨糖醇、葡萄糖水溶液中的热特性、回生特性以及流变特性的变化规律。DSC测试表明，添加山梨糖醇、葡萄糖和甘油溶液（其与水比例为1:1）后，SNPs的起始糊化温度分别增加了10.85 ℃、10.96 ℃和15.02 ℃，SNPs的终止糊化温度分别增加了9.29 ℃、9.17 ℃、12.40 ℃。回生结果表明，增塑剂会抑制SNPs的回生。随着浓度增加，SNPs在增塑剂体系中储能模量明显增加，且损耗模量大于储能模量，凝胶性增强。20% SNPs在山梨糖醇溶液和甘油溶液中的储能模量是10 Pa?s左右，而在葡萄糖溶液中大于1000 Pa?s，在葡萄糖溶液中损耗模量在100~500 Pa?s，说明SNPs葡萄糖水溶液具有更强的凝胶性。本文为SNPs在不同增塑剂中制备可降解膜提供理论依据。
Waxy maize starch was used as the raw material in this work, and starch nanoparticles (SNPs) were prepared through recrystallization of short-chain amylose and debranching using pullulanase. The patterns of the changes in the thermal, retrogradation, and rheological properties of the different concentrations of SNPs in aqueous glycerin, sorbitol, and glucose solutions were studied using a differential scanning calorimeter (DSC) and a dynamic rheometer. The results of the DSC showed that with the addition of sorbitol, glucose, and glycerol solutions (plasticizer/water ratio: 1:1 m/m), the gelatinization onset temperatures of SNPs were increased by 10.85 ℃, 10.96 ℃, and 15.02 ℃, respectively, and the gelatinization conclusion temperatures of SNPs were increased by 9.29 ℃, 9.17 ℃, and 12.40 ℃, respectively. The retrogradation test indicated that the plasticizers could inhibit the retrogradation of SNPs. When the content of SNPs increased, the storage modulus of SNPs in the plasticizer system increased markedly, the loss modulus was greater than the storage modulus, and the gelation properties were enhanced. For 20% SNPs, the storage modulus was around 10 Pa?s in sorbitol solution and glycerin solution, and more than 1000 Pa?s in glucose solution; the loss modulus was in the range of 100~500 Pa?s in glucose solution, indicating that the SNPs-glucose solution exhibited stronger gelation properties. This study provides a theoretical basis for the production of biodegradable starch films with SNPs in different plasticizers.