基于浓缩诱导型胶凝技术的米淀粉分子结构状态的调控机理研究

The phenomenon of becoming hard and difficult to digest usually occurs in the storage of rice staple food, but it likely can be changed fundamentally through controlling the structural state of rice starch molecules. The concentration-induced alginate gelling method firstly developed by the applicant is a gelling technology which can change the Ca2+-containing aqueous system of sodium alginate from a solution state to a gel state, so the concentration-induced alginate gelling process can be perfectly combined into the gelatinization process of starch. Apparently, the combination of the alginate gelling process and the starch gelatinization process provides a good entry point for the research on controlling the structural state of rice starch molecules. The project intends to use the concentration-induced gelling technology to investigate the regulation mechanism of the structural state of rice starch molecules for the purpose of improving the quality of rice staple food. The research content of the project mainly includes preparing and structure analyzing the system of combined processes of concentration-induced alginate gelation and rice starch gelatinization, detecting structural state of the rice starch molecules immobilized by the alginate gel, investigating the effect of gel solidification on the retrogradation and digestion properties of rice starch, and propounding a strategy on controlling the structural state of rice starch molecules. The research work of the project will help to promote the development of the industrialization of traditional rice staple food.

米制主食品在贮藏过程中经常出现变硬、难消化等品质劣变现象，但这些现象很可能可以通过调控米淀粉分子结构状态的方式得到根本性的改变。由申请人首创的浓缩诱导型海藻酸钠胶凝方法是一项全新的通过水分蒸发作用将含钙离子海藻酸钠水溶性体系从溶液状态转变成凝胶状态的胶凝技术，能够使海藻酸钠的胶凝过程与淀粉的糊化过程完美地结合为一体，从而为调控米淀粉分子结构状态提供了一个很好的研究切入点。本项目拟利用浓缩诱导型胶凝技术研究米淀粉分子结构状态的调控机理，以期为提高米制主食品品质提供新的方法依据。项目的研究内容主要包括浓缩诱导型海藻酸钠胶凝-米淀粉糊化体系的构建及体系结构变化的分析，凝胶固定化米淀粉分子结构的检测，凝胶固化作用对米淀粉回生作用与消化特性影响规律的研究，以及米淀粉分子结构状态调控策略的提出。本项目的研究工作将有利于促进传统米制主食品的工业化发展。

米制主食品在贮藏过程中经常出现的变硬、难消化等品质劣变现象很可能可以通过利用浓缩诱导型海藻酸钠凝胶调控大米淀粉分子结构状态的方式得到根本性的改变。本项目主要研究了浓缩诱导型海藻酸钠胶凝与大米淀粉糊化共存体系的构建条件，浓缩诱导型海藻酸钠胶凝过程对大米淀粉糊化分子结构状态的影响，浓缩诱导型海藻酸钠凝胶对大米淀粉分子结构状态的固化作用，凝胶固化作用对大米淀粉回生与消化特性的影响规律和利用浓缩诱导型胶凝技术调控大米淀粉分子结构状态的策略。结果表明：当海藻酸钠和钙离子浓度分别为1%和3 mmol/L而大米淀粉添加量为4%-6% 时，在热处理引起的水分蒸发过程中能形成海藻酸钠胶凝与大米淀粉糊化共存体系；浓缩诱导型海藻酸钠凝胶能够相对固化大米淀粉糊结构状态，有效延缓大米淀粉回生和显著影响大米淀粉的消化特性，在包括含有米糠膳食纤维的米面制品中具有良好的应用前景。本项目研究解决了如何利用浓缩诱导型胶凝技术调控大米淀粉分子结构状态的科学问题，并为应用浓缩诱导型海藻酸钠凝胶提高淀粉基食品品质提供了理论依据。