title: Molecular disassembly of rice and lotus starches during thermal processing and its effect on starch digestibility.
abstract: The molecular disassembly of starch during thermal processing is a major determinant for the susceptibility of starch to enzymatic digestion. In the present study, the effects of thermal processing on the disassembly of the granular structure and the in vitro enzymatic digestibility of rice and lotus starches were investigated. After heating at 50 °C, rice and lotus starches did not show significant changes in granular morphology, long-range crystallinity and short-range molecular order. As the temperature increased to 60 °C, rice starch underwent a partial gelatinization followed by an incomplete disruption of granular morphology, crystallites and molecular order. In contrast, lotus starch was almost completely gelatinized at 60 °C. At 70 °C or higher, both starches were fully gelatinized with complete disruption of the micro and macro structures. Our results show that gelatinization greatly increased the in vitro enzymatic digestibility of both starches, but that the degree of disassembly of the starch structure during thermal processing was not a major determinant of the digestibility of gelatinized starch.
authors.affiliation: Key Laboratory of Food Nutrition and Safety, Ministry of Education, College of Food Engineering and Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, China. sjwang@tust.edu.cn s.wang@tust.edu.cn and Tianjin Food Safety & Low Carbon Manufacturing Collaborative Innovation Center, Tianjin 300457, China.
authors.forename: Shujun
authors.initials: S
authors.lastname: Wang
authors.affiliation: Key Laboratory of Food Nutrition and Safety, Ministry of Education, College of Food Engineering and Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, China. sjwang@tust.edu.cn s.wang@tust.edu.cn.
authors.forename: Yue
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Key Laboratory of Food Nutrition and Safety, Ministry of Education, College of Food Engineering and Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, China. sjwang@tust.edu.cn s.wang@tust.edu.cn.
authors.forename: Jinrong
authors.initials: J
authors.lastname: Wang
authors.affiliation: Key Laboratory of Food Nutrition and Safety, Ministry of Education, College of Food Engineering and Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, China. sjwang@tust.edu.cn s.wang@tust.edu.cn and Tianjin Food Safety & Low Carbon Manufacturing Collaborative Innovation Center, Tianjin 300457, China.
authors.forename: Shuo
authors.initials: S
authors.lastname: Wang
authors.affiliation: Plant Breeding Institute, Faculty of Agriculture and Environment, The University of Sydney, NSW 2006, Australia.
authors.forename: Les
authors.initials: L
authors.lastname: Copeland
mesh_terms: D004063:Digestion; D005511:Food Handling; D006358:Hot Temperature; D000070116:Lotus / Q000737:chemistry*; D012275:Oryza / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013213:Starch / Q000737:chemistry*
chemical_list: D013213:Starch