Microwave treatment regulates the free volume of rice starch
Microwave treatment regulates the free volume of rice starch
复制标题
微波处理调节大米淀粉的自由体积
DOI：
10.1038/s41598-019-40598-3
复制
发表时间：
2019
影响因子：
4.6
通讯作者：
Zhang Hao
中科院分区：
文献类型：
--
作者：
Yan Bowen;Shen Huijie;Fan Daming;Tao Yuan;Wu Yejun;Wang Mingfu;Zhao Jianxin;Zhang Hao
利用正电子湮没寿命谱（帕尔斯）研究微波参数和水分含量对大米淀粉自由体积（FV）变化的影响，探讨FV变化与大米淀粉理化性质之间的潜在关系。微波加热和水分子的作用使淀粉的FV增加。然而，这一结果很大程度上受到水分子增塑的影响。在微波加热过程中，水分蒸发引起的反增塑作用导致FV的尺寸和浓度降低。小角X射线散射（SAXS）结果表明，微波加热后大米淀粉的无定形区厚度显著减小（p < 0.05），玻璃化转变温度（Tg）和糊化温度显著升高（p <0.05）。相关性分析表明，功率强度和加热时间与o-Ps的寿命呈负相关。此外，大米淀粉的无定形区和Tg的变化与FV的变化密切相关。研究结果为进一步研究微波处理对淀粉糊的定向调控和改善淀粉糊食品品质提供了理论依据。
The aim of this work was to investigate the role of microwave parameters and moisture content on the free volume (FV) changes of rice starch by positron annihilation lifetime spectroscopy analysis (PALS) and to explore the potential relationship between the changes of FV and physicochemical properties of rice starch. Microwave heating and water molecules lead to the increasing of FV of starch. However, this result is largely influenced by the plasticization of water molecule. The anti-plasticization caused by water evaporation resulting in a decrease in the size and concentration of FV during microwave heating. Significant decrease (p < 0.05) in the thickness of amorphous region of microwave-heated rice starch was found by small angle X-ray scattering (SAXS), and the glass transition temperature (Tg) and gelatinization temperature significantly increase (p < 0.05) after microwave heating. According to correlation analysis, the power intensity and heating time were correlated negatively with the lifetime of o-Ps. In addition, the changes of amorphous region andTgof rice starch were strongly related to FV changes. These results provided a theoretical basis for further research on the directional regulation of FV and improvement the quality of starch-based food by using microwave treatment.