Department of Food Science, University of Wisconsin-Madison, Madison, WI 53706, USA.
Food Chem. 2022 Nov 1;393:133331. doi: 10.1016/j.foodchem.2022.133331. Epub 2022 May 28.
Understanding wheat gliadin-proanthocyanidin (PA) interactions would be useful to systematically control foams and gels, create novel textures, and reduce inflammatory reactions. This work aimed to determine the effects of heat (50-90 °C) on gliadin-proanthocyanidin (PA) interactions. Gliadin-PA mixtures were heated for 30 min in aqueous ethanol, and resulting morphology, fluorescence, and MW distribution were analyzed. Atomic force microscopy showed that PA greatly increased gliadin particle size, especially with heat. PA significantly quenched gliadin's tryptophan fluorescence. Further fluorescence data analysis indicated that PA interacted with gliadins through static quenching, primarily via hydrophobic interactions, and that 75 °C treatment yielded the greatest gliadin-PA interactions, likely because the proteins unraveled and exposed residues for interaction. PA appeared to interact mostly with ω-gliadins, based on their absence in the SDS-PAGE gel. Though it has been overshadowed in previous studies by non-covalent interactions, staining of quinoproteins indicated that PA covalently cross-linked gliadins at pH ∼ 6.
了解小麦醇溶蛋白-原花青素（PA）的相互作用将有助于系统地控制泡沫和凝胶，创造新的质地，并减少炎症反应。本工作旨在确定热（50-90°C）对醇溶蛋白-原花青素（PA）相互作用的影响。醇溶蛋白-PA 混合物在含水乙醇中加热 30 分钟，分析其形态、荧光和 MW 分布。原子力显微镜显示，PA 大大增加了醇溶蛋白颗粒的大小，尤其是在加热的情况下。PA 显著猝灭了醇溶蛋白的色氨酸荧光。进一步的荧光数据分析表明，PA 通过静态猝灭与醇溶蛋白相互作用，主要通过疏水相互作用，75°C 处理产生最大的醇溶蛋白-PA 相互作用，可能是因为蛋白质展开并暴露了用于相互作用的残基。根据 SDS-PAGE 凝胶中不存在的情况，PA 似乎主要与ω-醇溶蛋白相互作用。尽管在以前的研究中，非共价相互作用掩盖了它的存在，但醌蛋白的染色表明 PA 在 pH~6 时共价交联了醇溶蛋白。
