Wang Shujun, Sun Yue, Wang Jinrong, Wang Shuo, Copeland Les
Key Laboratory of Food Nutrition and Safety, Ministry of Education, College of Food Engineering and Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, China.
Plant Breeding Institute, Faculty of Agriculture and Environment, The University of Sydney, NSW 2006, Australia.
Food Funct. 2016 Feb;7(2):1188-95. doi: 10.1039/c6fo00067c.
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.
热加工过程中淀粉的分子拆解是决定淀粉对酶消化敏感性的主要因素。在本研究中，考察了热加工对大米淀粉和莲子淀粉颗粒结构拆解以及体外酶消化率的影响。在50℃加热后，大米淀粉和莲子淀粉的颗粒形态、长程结晶度和短程分子有序性均未显示出显著变化。当温度升至60℃时，大米淀粉发生部分糊化，随后颗粒形态、微晶和分子有序性出现不完全破坏。相比之下，莲子淀粉在60℃时几乎完全糊化。在70℃及以上，两种淀粉均完全糊化，微观和宏观结构完全破坏。我们的结果表明，糊化极大地提高了两种淀粉的体外酶消化率，但热加工过程中淀粉结构的拆解程度并非糊化淀粉消化率的主要决定因素。
