Effect of Alkali Treatment on Structure and Properties of High Amylose Corn Starch Film
Effect of Alkali Treatment on Structure and Properties of High Amylose Corn Starch Film
复制标题
碱处理对高直链玉米淀粉膜结构与性能的影响
作者：
Yang Qin;Hui Zhang;Yangyong Dai;Hanxue Hou;Haizhou Dong
碱处理用于玉米淀粉熔融挤出成膜，但该过程的最佳条件仍然未知。在这项研究中，研究了通过熔融挤出制备的高直链玉米淀粉（70%）薄膜在不同浓度的氢氧化钠（NaOH）下的性能和结构的变化。随着氢氧化钠浓度的增加，高直链淀粉膜的拉伸强度逐渐下降，而断裂伸长率则逐渐增加。 2% NaOH处理的高直链淀粉（HAS）膜的拉伸强度为10.03 MPa，断裂伸长率为40%。 2%NaOH处理促进淀粉分子有序重排，形成Eh型晶体结构，扩大了单螺旋结构的间距，增加了淀粉分子的活动性，减缓了重结晶过程； 10% NaOH处理在挤压过程中氧化高直链玉米淀粉的羟基，形成多羰基结构，引发淀粉分子链的降解和交联。
Alkali treatment is used for melt extrusion film formation with corn starch, but optimal conditions for this procedure are still unknown. In this study, the changes in properties and structure of high amylose corn starch (70%) films with different concentrations of sodium hydroxide (NaOH), prepared by melting extrusion, were investigated. With increasing sodium hydroxide concentrations, the tensile strength of the high-amylose starch film decreased gradually, while the elongation at break increased. The tensile strength of the high amylose starch (HAS) film with 2% NaOH-treatment was 10.03 MPa and its elongation at break was 40%. A 2% NaOH-treatment promoted the orderly rearrangement of starch molecules and formed an Eh-type crystal structure, which enlarged the spacing of the single helix structure, increased the molecular mobility of the starch, and slowed down the process of recrystallization; a 10% NaOH-treatment oxidized the hydroxyl groups of the high amylose corn starch during extrusion, formed a poly-carbonyl structure, and initiated the degradation and cross-linking of starch molecule chains.