title: Effect of defatting on acid hydrolysis rate of maize starch with different amylose contents.
abstract: The effect of defatting on the physiochemical properties and the acid hydrolysis rate of maize starch with different amylose contents was evaluated in this study. The increase in the number of pores and the stripping of starch surface layers were observed after defatting by scanning electron microscopy. X-ray diffraction spectrum showed that the peaks attributing to the amylose-lipid complex disappeared. The relative crystallinity increased by 19% for high-amylose maize starch (HMS) on defatting, while the other tested starches virtually unchanged. Differential scanning calorimetry study indicated an increase in the thermal stability for the defatted starches. Compared with native waxy maize starch, the acid hydrolysis rate of the defatted one increased by 6% after 10 days. For normal maize starch (NMS) and HMS, the higher rate of hydrolysis was observed during the first 5 days. Thereafter, the hydrolysis rate was lower than that of their native counterpart. The increase in susceptibility to acid hydrolysis (in the first 5 days) was mainly attributed to the defective and porous structures formed during defatting process, while the decrease of hydrolysis rate for NMS and HMS samples (after the first 5 days) probably resulted from the increase in the relative crystallinity.
authors.affiliation: The State Key Laboratory of Food Science and Technology, 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: Benxi
authors.initials: B
authors.lastname: Wei
authors.forename: Xiuting
authors.initials: X
authors.lastname: Hu
authors.forename: Bao
authors.initials: B
authors.lastname: Zhang
authors.forename: Hongyan
authors.initials: H
authors.lastname: Li
authors.forename: Xueming
authors.initials: X
authors.lastname: Xu
authors.forename: Zhengyu
authors.initials: Z
authors.lastname: Jin
authors.forename: Yaoqi
authors.initials: Y
authors.lastname: Tian
mesh_terms: D000143:Acids / Q000737:chemistry*; D000688:Amylose / Q000737:chemistry*; D006868:Hydrolysis; D008055:Lipids / Q000737:chemistry; D013213:Starch / Q000737:chemistry* / Q000648:ultrastructure; D013816:Thermodynamics; D014961:X-Ray Diffraction; D003313:Zea mays / Q000737:chemistry*
chemical_list: D000143:Acids; D008055:Lipids; D013213:Starch; D000688:Amylose
keywords: Acid hydrolysis rate; Defatting; Maize starch; Physiochemical