Hainan University-HSF/LWL Collaborative Innovation Laboratory, School of Food Science and Engineering, Hainan University, 58 People Road, Haikou 570228, PR China.
SCUT-Zhuhai Institute of Modern Industrial Innovation, School of Food Science and Engineering, South China University of Technology, 381 Wushan Road, Guangzhou 510640, PR China; Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, Guangzhou 510640, PR China; Overseas Expertise Introduction Center for Discipline Innovation of Food Nutrition and Human Health (111 Center), Guangzhou, PR China.
Carbohydr Polym. 2024 Apr 1;329:121790. doi: 10.1016/j.carbpol.2024.121790. Epub 2024 Jan 10.
Glycosylation is a method that enhances the functional properties of proteins by covalently attaching sugars to them. This study aimed at preparing three conjugates (WP-HG, WP-SBP, and WP-RGI) by dry heating method to research the influence of different pectin structures on the functional properties of WP and characterize properties and structures of these conjugates. The research results manifested that the degree of glycosylation (DG) of HG, SBP and RGI were 13.13 % ± 0.07 %, 23.27 % ± 0.3 % and 36.39 % ± 0.3 % respectively, suggesting that the increase of the number of branch chains promoted the glycosylation reaction. The formation of the conjugate was identified by the FT-IR spectroscopy technique. And SEM showed that WP could covalently bind to pectin, resulting in a smoother and denser surface of the conjugates. The circular dichroism analysis exhibited that the glycosylation reaction altered the secondary structure of WP and decreased the α-Helix content. This structural change in the protein spatial conformation led to a decrease in the hydrophobicity of protein surface. But the addition of pectin further regulated the hydrophilic-hydrophobic ratio on the surface of the protein, thus improving the emulsification properties of WP. In addition, the glycosylation could improve the stability of the emulsion, giving it a smaller droplet size, higher Zeta-potential and more stable properties. In a word, this study pointed out the direction for the application of different pectin structures in the development of functional properties of glycosylation products in food ingredients.
糖基化是一种通过将糖共价连接到蛋白质上来增强其功能特性的方法。本研究旨在通过干法加热法制备三种缀合物（WP-HG、WP-SBP 和 WP-RGI），研究不同果胶结构对 WP 功能特性的影响，并对这些缀合物的性质和结构进行表征。研究结果表明，HG、SBP 和 RGI 的糖基化程度（DG）分别为 13.13%±0.07%、23.27%±0.3%和 36.39%±0.3%，表明支链数量的增加促进了糖基化反应。FT-IR 光谱技术鉴定了缀合物的形成。SEM 表明 WP 可以与果胶共价结合，导致缀合物表面更加光滑和致密。圆二色性分析表明，糖基化反应改变了 WP 的二级结构，降低了α-螺旋含量。这种蛋白质空间构象的结构变化导致蛋白质表面疏水性降低。但果胶的添加进一步调节了蛋白质表面的亲疏水性比例，从而改善了 WP 的乳化性能。此外，糖基化可以提高乳液的稳定性，使其粒径更小、Zeta 电位更高、性质更稳定。总之，本研究为不同果胶结构在食品配料中糖基化产物功能性质开发中的应用指明了方向。
