In this study, the interactions between myofibrillar proteins (MPs) and key heterocyclic flavor compounds, 2-ethyl-6-methylpyrazine, 2-acetylpyrrole, 2-acetyl-thiazole, and 2-acetyl-2-thiazoline, in beef, were investigated using solid phase microextraction (SPME) combined with gas chromatography-mass spectrometry (GC–MS), spectroscopic, and followed by molecular docking. The GC–MS results revealed that the molecular structures of the flavor compounds strongly influenced their binding affinity with MPs. 2-Ethyl-6-methylpyrazine and 2-acetylpyrrole exhibited salting-out effects from the MPs solution, and 2-acetyl-2-thiazoline displayed a higher binding affinity with MPs compared to 2-acetyl-thiazole, indicated by the Hill binding models. Fluorescence static quenching experiments also demonstrated that 2-acetyl-2-thiazoline had a higher Stern–Volmer constant with MPs than 2-acetyl-thiazole. Circular dichroism analysis revealed that increased concentrations of flavor compounds transformed ordered structures in MPs into random coils. This suggests that high molar concentrations of 2-acetyl-thiazole and 2-acetyl-2-thiazoline induced conformational changes in MPs. In accordance with the molecular docking model, hydrogen bonds, van der Waals forces, and hydrophobic interactions were identified as the primary noncovalent interactions between MPs and 2-acetyl-thiazole and 2-acetyl-2-thiazoline. This study provides valuable insights for controlling flavor profiles of beef products.

中文翻译：

---

使用 SPME-GC-MS、光谱和分子对接方法研究选定的杂环风味化合物和牛肉肌原纤维蛋白之间的相互作用


在这项研究中，研究了牛肉中肌原纤维蛋白 (MP) 与关键杂环风味化合物 2-乙基-6-甲基吡嗪、2-乙酰吡咯、2-乙酰基-噻唑和 2-乙酰基-2-噻唑啉之间的相互作用使用固相微萃取（SPME）结合气相色谱-质谱（GC-MS）、光谱，然后进行分子对接。 GC-MS 结果表明，风味化合物的分子结构强烈影响其与 MP 的结合亲和力。 Hill 结合模型表明，2-乙基-6-甲基吡嗪和 2-乙酰吡咯在 MPs 溶液中表现出盐析效应，并且与 2-乙酰基-噻唑相比，2-乙酰基-2-噻唑啉与 MPs 表现出更高的结合亲和力。荧光静态猝灭实验还表明，2-乙酰基-2-噻唑啉与 MP 相比，具有比 2-乙酰基-噻唑更高的 Stern-Volmer 常数。圆二色性分析表明，风味化合物浓度的增加将 MP 中的有序结构转变为随机卷曲。这表明高摩尔浓度的 2-乙酰基-噻唑和 2-乙酰基-2-噻唑啉诱导 MP 的构象变化。根据分子对接模型，氢键、范德华力和疏水相互作用被确定为MP与2-乙酰基-噻唑和2-乙酰基-2-噻唑啉之间的主要非共价相互作用。这项研究为控制牛肉产品的风味特征提供了宝贵的见解。