高压均质对EGCG-OSA玉米淀粉复合体的结构及其抗氧化特性的影响

Effect of High Pressure Homogenization on the Structure and Antioxidant Properties of EGCG-OSA Corn Starch Complex

为探究高压均质作用对EGCG-OSA玉米淀粉复合体的影响,分别采用加热、高压均质以及先高压均质后加热的方法制备了EGCG-OSA玉米淀粉复合体,利用傅里叶红外(FT-IR)、X射线衍射(XRD)与电镜扫描(SEM)对其结构、形貌进行表征;利用高级流变仪以及粒度仪对其流变性进行研究;通过测定复合物的DPPH和ABTS自由基清除率比较其抗氧化活性。结果表明:三种复合体均有很高的抗氧化性,并且三种复合体的抗氧化性随储藏时间下降的幅度较小,其中用先均质后加热方式制备的复合体具有最高的抗氧化性,在30 d后DPPH清除率仍能达到89.63%,ABTS自由基清除率达到98.66%;FT-IR与XRD结果表明复合物并没有产生新的化学键和官能团;流变性测试结果则表明:经过高压均质作用后的复合体,黏度下降幅度更大,粒径也有所减小。综上表明,通过先高压均质后加热方式制备的复合体具有更高的抗氧化性和更为优良的储藏稳定性,研究结果能为EGCG在淀粉类食品的加工及生产中的应用提供理论及实验基础。

Aiming to investigate the effect of high pressure homogenization on EGCG-OSA corn starch complex, EGCGOSA corn starch complex was prepared by heating, high pressure homogenization and high pressure homogenization followed by heating respectively. Also, Fourier infrared(FT-IR), X-ray diffraction(XRD), scanning electron microscope(SEM) was utilized to characterize its structure and morphology. Rheometer and particle size analyzer was applied to analyze its rheology;and the DPPH and ABTS free radical scavenging rate was measured to compare the oxidation resistance. The research results indicated that the three kinds of complexes had high oxidation resistance, and the decline within the number of days was insignificant. Among these complexes, the one generated by sequential homogenization and heating obtained the highest oxidation resistance, and the DPPH clearance rate after 30 days still reached 89.63%, besides,the ABTS free radical scavenging rate reached 98.66%. According to the infrared and X-ray results, there was no evidence that the composite had any new chemical bonds or functional groups;the rheological results illustrated that the viscosity of the composite after high-pressure homogenization decreased more and its particle size was reduced. In summary, the complex prepared by high pressure homogenization followed by heating has higher oxidation resistance and better storage stability, which provides theoretical and experimental basis for the application of EGCG in the processing and production of starch food.