The Effects of Temperature on Starch Molecular Conformation and Hydrogen Bonding

Starch is an important resource in nature and heating is a frequently used processing method. In the process of starch processing, the changes of starch molecular conformation play a decisive role on starch physicochemical properties. Meanwhile, hydrogen bond is an important interaction force for maintaining starch structure. Therefore, molecular dynamics simulation is used to explore the effects of temperature on starch molecular conformation and hydrogen bonds. The results show that, firstly, heating can unwind the double-amylose helix and improve the bending degree of starch molecules, indicating that heating treatment is destructive to the crystalline region. Secondly, starch molecules will become more unstable with the increase of temperature, which may be the key factor of heating induced starch gelatinization starch. Thirdly, heating will increase the intramolecular hydrogen bonds and decrease the starch-water hydrogen bonds. Meanwhile, the hydrogen bond distributions in starch molecules are also clarified. The results can be complementary to the existing experimental phenomena about the effects of temperature on starch properties, and provide a reference for the fully explanation of the effects mechanism of heating on starch. Meanwhile, the results can also provide a reference for the using of heating in starch processing and the research of starch granule structure.