Protein conformational rearrangement triggered by adsorption to the hydrophobic interface of oil droplets has long been considered as a key factor in emulsification. In this study, an alkaline pH-shifting-driven conformational adaptation enhanced interfacial proteins was used to improve their stability against heat-induced flocculation of myosin emulsions. We used the unfolded myosin at pH 12 to emulsify soy oil and then readjusted the pH of the emulsion to neutral. The corresponding myosin emulsion (0.5% w/v protein, 10% v/v soy oil, and 0.6 M NaCl) almost not flocculated when heated at 75 °C for 30 min. Moreover, after thermal treatment, the particle size of the emulsion was not significantly increased (P > 0.05) and the emulsion did not exhibit a creaming phenomenon after a week. Based on the circular dichroism and Fourier transform infrared analysis, we speculated the superiority of the emulsion is closely related to the alkaline pH-shifting-driven conformational adaptation enhanced interfacial protein. Additionally, the resulting steric stabilization in overcoming the attractive hydrophobic forces between denatured protein molecules coated droplets might be the main factor for the inhibition of heat-induced flocculation of the emulsion. Our research may have important implications for the formulation of protein-stabilized oil-in-water emulsions.

中文翻译：

---

碱性pH位移驱动方法通过构象适应增强界面蛋白通过立体排斥来抑制肌球蛋白基乳液的热诱导絮凝

长期以来，由吸附到油滴的疏水界面引发的蛋白质构象重排一直被认为是乳化的关键因素。在这项研究中，使用碱性pH值驱动的构象适应增强界面蛋白来提高其抵抗肌球蛋白乳液热诱导絮凝的稳定性。我们使用pH 12展开的肌球蛋白来乳化大豆油，然后将乳液的pH值重新调节至中性。当在75°C加热30分钟时，相应的肌球蛋白乳液（0.5％w / v蛋白，10％v / v大豆油和0.6 M NaCl）几乎不絮凝。此外，热处理后，乳液的粒径没有显着增加（P> 0.05），并且一周后乳液未显示出乳霜现象。基于圆二色性和傅立叶变换红外分析，我们推测乳液的优越性与碱性pH位移驱动的构象适应性增强的界面蛋白密切相关。另外，在克服变性的蛋白质分子包被的小滴之间有吸引力的疏水力上所得到的空间稳定性可能是抑制乳液热诱导絮凝的主要因素。我们的研究可能对蛋白质稳定的水包油型乳化液的配方具有重要意义。