Department of Chemical Engineering, Federal University of Rio Grande do Norte, Natal, RN, Brazil.
Department of Chemical Engineering, Federal University of Campina Grande, Campina Grande, PB, Brazil.
Int J Biol Macromol. 2023 Dec 31;253(Pt 5):127030. doi: 10.1016/j.ijbiomac.2023.127030. Epub 2023 Sep 23.
The objective of this study was to investigate the dual modification of red rice starch using pulsed electric field (PEF) and α-amylase, focusing on morpho-structural, thermal, and viscoamylographic properties. Native starch (Control) underwent various treatments: PEF at 30 kV cm (PEF30), α-amylase at 9.0 U mg (AA0), and a combination of both (PEF30 + α and α + PEF30). The PEF30 + α treatment exhibited the highest degree of digestion (10.66 %) and resulted in morphological changes in the starch granules, which became elongated and curved, with an increased average diameter of 50.49 μm compared to the control. The starch was classified as type A, with a maximum reduction in crystallinity of up to 21.17 % for PEF30. The deconvolution of FT-IR bands indicated an increase in the double helix degree (DDH) for PEF30 and AA0, while the degree of order (DO) was reduced for PEF30, AA0, and PEF30 + α. DSC analysis revealed significant modifications in gelatinization temperatures, particularly for PEF30, and these changes were supported by a reduction in gelatinization enthalpy (ΔH) of up to 28.05 % for AA0. These findings indicate that both individual and combined treatments promote a decrease in starch gelatinization and facilitate the process, requiring less energy. Differences were observed between the formulations subjected to single and alternating dual treatments, highlighting the influence of the order of PEF application on the structural characteristics of starch, especially when applied before the enzymatic treatment (PEF + α). Regarding the viscoamylographic parameters, it was observed that AA0 presented higher values than the control, indicating that α-amylase enhances the firmness of the paste. The double modification with PEF + α was more effective in reducing syneresis and starch retrogradation, leading to improvements in paste properties. This study provided significant insights into the modification of red rice starch using an efficient and environmentally friendly approach.
本研究旨在探讨利用脉冲电场（PEF）和α-淀粉酶对红米淀粉进行双重修饰，重点研究其形态结构、热学和黏滞性特性。天然淀粉（对照）经历了不同的处理：30kV/cm 的 PEF（PEF30）、9.0U/mg 的α-淀粉酶（AA0）和两者的组合（PEF30+α 和 α+PEF30）。PEF30+α 处理的消化程度最高（10.66%），导致淀粉颗粒形态发生变化，颗粒变得细长弯曲，平均直径增加到 50.49μm，与对照相比。淀粉被分类为 A 型，最大结晶度降低高达 21.17%的 PEF30。FT-IR 带的解卷积表明，PEF30 和 AA0 的双螺旋度（DDH）增加，而 PEF30、AA0 和 PEF30+α 的有序度（DO）降低。DSC 分析表明，糊化温度发生了显著变化，特别是对于 PEF30，并且这些变化得到了 AA0 中高达 28.05%的糊化焓（ΔH）降低的支持。这些发现表明，单独和组合处理都促进了淀粉糊化的降低，并使该过程更容易进行，所需能量更少。在单一和交替双重处理的制剂之间观察到差异，突出了 PEF 应用顺序对淀粉结构特性的影响，尤其是在酶处理之前（PEF+α）应用时。关于黏滞性参数，观察到 AA0 比对照具有更高的值，表明α-淀粉酶增强了糊的硬度。PEF+α 的双重修饰在减少渗出和淀粉回生方面更有效，导致糊性质的改善。本研究为利用高效环保的方法对红米淀粉进行修饰提供了重要的见解。
