School of Food Science and Engineering, South China University of Technology, Guangzhou 510641, China.
School of Food Science and Engineering, South China University of Technology, Guangzhou 510641, China; Overseas Expertise Introduction Center for Discipline Innovation of Food Nutrition and Human Health (111 Center), Guangzhou 510641, China.
Food Chem. 2019 Jul 30;287:93-99. doi: 10.1016/j.foodchem.2019.02.060. Epub 2019 Feb 21.
The influence of pH-induced structural modifications of myofibrillar proteins (MPs) on their interaction mechanisms with pyrazine compounds was investigated. At a lower pH (4.9, 5.5), MPs aggregated to larger particle sizes due to enhanced the protein-protein interactions. The binding with pyrazine compounds was strongly affected by pH and the nature of flavor compounds. MPs exhibited flavor releasing behavior, probably due to protein-protein interactions and surface tension. Fluorescence analysis revealed that the interaction of pyrazine compounds with MPs followed a combination of static and dynamic quenching. The changes in quenching constant (K) might be attributed to a dynamic quenching, probably due to protein aggregation. The percentages of free 2,5-Dimethylpyrazine (2,5-DMP) were similar to K. Thermodynamic parameters indicated that electrostatic interactions and hydrophobic interactions were the major acting forces in the binding of MPs to 2,5-DMP. The binding of 2,5-DMP increased the α-helix content of MPs.
研究了肌原纤维蛋白 (MPs) 的 pH 诱导结构修饰对其与吡嗪类化合物相互作用机制的影响。在较低的 pH（4.9、5.5）下，由于蛋白质-蛋白质相互作用增强，MPs 聚集到更大的颗粒尺寸。与吡嗪类化合物的结合受 pH 和风味化合物性质的强烈影响。MPs 表现出释放风味的行为，可能是由于蛋白质-蛋白质相互作用和表面张力。荧光分析表明，吡嗪类化合物与 MPs 的相互作用遵循静态和动态猝灭的组合。猝灭常数 (K) 的变化可能归因于动态猝灭，可能是由于蛋白质聚集。游离 2,5-二甲基吡嗪（2,5-DMP）的百分比与 K 相似。热力学参数表明，静电相互作用和疏水相互作用是 MPs 与 2,5-DMP 结合的主要作用力。2,5-DMP 的结合增加了 MPs 的α-螺旋含量。
