title: Thermal degradation behavior of hypochlorite-oxidized starch nanocrystals under different oxidized levels.
abstract: The thermal degradation behavior of hypochlorite-oxidized starch nanocrystals (OSNCs) was evaluated in this study. Carbonyl and carboxyl groups in OSNCs increased from 0.006 and 0.091mmol/g to 0.033 and 0.129mmol/g, respectively, as the active chlorine concentration increased from 1% to 4% (w/w). Compared with starch nanocrystals (SNCs), the initial degradation temperature of OSNCs with 4% oxidization decreased from 273°C to 253°C. Two degradation processes were detected using differential thermal analysis. The activation energy of the low-temperature process increased with increasing oxidization level because of removal of sulfate esters and reduction of the decomposition products of H2O during oxidation. With increasing temperature, the H2O generating from decarboxylation and decomposition of the carboxyl groups may catalyze SNCs depolymerization, leading to decrease in the activation energy of the high-temperature process. OSNCs (4% oxidized level) can be used in dry process below 253°C to avoid degradation.
authors.affiliation: The State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
authors.forename: Benxi
authors.initials: B
authors.lastname: Wei
authors.affiliation: The State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
authors.forename: Hongyan
authors.initials: H
authors.lastname: Li
authors.affiliation: The State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China. Electronic address: yqtian@jiangnan.edu.cn.
authors.forename: Yaoqi
authors.initials: Y
authors.lastname: Tian
authors.affiliation: School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi 214122, China.
authors.forename: Xueming
authors.initials: X
authors.lastname: Xu
authors.affiliation: The State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi 214122, China.
authors.forename: Zhengyu
authors.initials: Z
authors.lastname: Jin
mesh_terms: D004055:Differential Thermal Analysis; D006358:Hot Temperature; D006997:Hypochlorous Acid / Q000737:chemistry*; D053758:Nanoparticles; D010084:Oxidation-Reduction; D013213:Starch / Q000737:chemistry*
chemical_list: D006997:Hypochlorous Acid; D013213:Starch
keywords: Hypochlorite oxidation; Starch nanocrystal; Thermal degradation