高浓度玉米淀粉酶解性能及反应机制研究

To reduce production cost of starch sugar, one of the most efficient ways is the increase in initial concentration of starch solution, which can obtain a high solid content of saccharified liquid and thus significantly decrease the energy consumption for concentrating saccharified liquid and wastewater emission. In this project, applied basic researches on performance and mechanism of enzymatic hydrolysis of corn starch, the main raw material of starch sugar production, at a high solid content will be carried out. Firstly, the effects of granular and molecular structures on enzymatic starch hydrolysis are analyzed to know starch structural characteristic related to enzymatic hydrolysis. Then, the correlation model between starch concentration and catalytic efficiency of amylase will be built. The effects of starch concentration on enzymatic starch hydrolysis will be studied as well as the mechanisms, which helps to reveal the regular pattern about enzymatic hydrolysis of corn starch at varied solid contents on the molecular level. Effects of amylase types and reaction conditions on enzymatic hydrolysis of corn starch at a high solid content will be examined and the qualities of enzymatic hydrolysate be evaluated and optimized, so that the control strategies for significantly improving enzymatic hydrolysis velocities of corn starch at a high solid content and its product qualities could be obtained. Finally, key technologies for saccharification and liquefaction of corn starch at a high solid content will be made a breakthrough. This project would theoretically guide to design technical process of enzymatic starch hydrolysis at a high solid content, and promote the rapid and healthy development of starch sugar and related industries.

为了降低淀粉糖的生产成本，最有效的途径之一是提高淀粉的初始浓度，使糖液中固含量增加，从而显著降低蒸发浓缩能耗，减少废水排放。本项目以淀粉糖最主要的生产原料玉米淀粉作为研究对象，对高浓度淀粉的酶解性能和反应机制进行一定的应用基础研究。首先分析淀粉颗粒结构与分子结构对其酶解性能影响，了解与淀粉酶解性能密切相关的结构特征；建立淀粉浓度与淀粉酶酶解效率之间的相关性模型，并解析淀粉浓度对玉米淀粉酶解机制的影响，探讨淀粉浓度对其酶解产生影响的机理，从分子水平揭示不同浓度玉米淀粉的酶解规律；深入分析淀粉酶种类、反应条件对高浓度玉米淀粉酶解反应的影响，并对高浓度玉米淀粉酶解产物的品质进行评估和优化，探索能明显改善高浓度玉米淀粉酶解速率和产品品质的调控策略。在此基础上，最终突破高浓度淀粉酶法液化、糖化过程中的关键技术，为高浓度淀粉酶解工艺技术路线的形成提供理论指导，促进淀粉糖及相关工业快速健康发展。

为了降低淀粉糖的生产成本，最有效的途径之一是提高淀粉的初始浓度，使糖液中固含量增加，从而显著降低蒸发浓缩能耗，减少废水排放。本项目以淀粉糖最主要的生产原料玉米淀粉作为主要研究对象，对高浓度淀粉的酶解性能和反应机制进行了应用基础研究。本项目将淀粉液化、糖化的初始浓度提高至45%~50%，采用α-淀粉酶、葡萄糖淀粉酶、β-淀粉酶、生淀粉酶等不同酶法催化技术，得到了高浓度淀粉酶法生产葡萄糖和麦芽糖的技术路线；通过温度控制、微波预处理、超声预处理以及复合酶辅助等调控策略改善了高浓度淀粉液化、糖化效率，并提高了产品得率，产品得率和品质接近实际工业生产。同时，本项目深入研究了淀粉初始浓度对玉米淀粉糊化和酶解过程的影响，解析淀粉浓度对玉米淀粉酶解机制的影响，探讨淀粉浓度对其酶解产生影响的机理，从分子水平揭示不同浓度玉米淀粉的酶解规律；深入分析淀粉分子结构对酶解性能的影响，建立淀粉分子精细结构与其酶解性能的相关性模型。在此基础上，最终突破高浓度淀粉酶法液化、糖化过程中的关键技术，为高浓度淀粉酶解工艺技术路线的形成提供理论指导，将促进淀粉糖及相关工业快速健康发展。