College of Food Science and Engineering, Northwest A & F University, China.
College of Forestry, Northwest A & F University, China; Shaanxi Jiangwo Runfeng Agricultural Development Co., Ltd, China.
Int J Biol Macromol. 2023 Dec 31;253(Pt 1):126626. doi: 10.1016/j.ijbiomac.2023.126626. Epub 2023 Sep 2.
Non-thermal dielectric barrier discharge plasma (DBDP) and four thermal treatments, including baking (BT), high pressure cooking (HPC), radio frequency (RF) and microwave (MW) were applied to modify the structural and physicochemical properties of Cyperus esculentus starch (CES). The results showed that the thermal treatments remarkably disordered the crystalline structures of CES through weakening the double-helix conformation of amylopectin, while DBDP caused much more gentle influence on the starch structures than them. Specifically, MW induced the high-frequency displacement of polar molecules and intensive collisions between starch and water molecules, causing the largest stretching and swelling extents of amylopectin, resulting in the highest pasting and rheological viscosity of CES in four thermal treatments. As DBDP did not favor the aggregation of amylopectin chains, the deaggregated starch chains promoted the hydration effects with water molecules, boosting the final pasting viscosity, apparent rheological viscosity, freeze-thaw stability and digestion velocity of CES. Besides, the gelatinization-retrogradation process in the thermal treatments regulated starch digestion velocity and produced type III resistant starch in CES. Conclusively, the modified physicochemical properties of CES resulted from the altered molecular structures of starch by the applied treatments.
非热介电阻挡放电等离子体（DBDP）和四种热处理方法，包括烘焙（BT）、高压蒸煮（HPC）、射频（RF）和微波（MW），被应用于修饰香蒲淀粉（CES）的结构和物理化学性质。结果表明，热处理通过削弱支链淀粉的双螺旋构象，显著地打乱了 CES 的结晶结构，而 DBDP 对淀粉结构的影响比它们温和得多。具体来说，MW 引起了极性分子的高频位移和淀粉与水分子之间的剧烈碰撞，导致支链淀粉的最大拉伸和膨胀程度，从而在四种热处理中使 CES 的糊化和流变粘度达到最高。由于 DBDP 不利于支链淀粉链的聚集，去聚集的淀粉链促进了与水分子的水合作用，提高了 CES 的最终糊化粘度、表观流变粘度、冻融稳定性和消化速度。此外，热处理中的糊化-回生过程调节了淀粉的消化速度，并在 CES 中产生了 III 型抗性淀粉。总之，CES 的改性物理化学性质是由处理所改变的淀粉分子结构引起的。
