Zang Jingnan, Qing Mingmin, Chi Yujie, Chi Yuan
College of Food Science, Northeast Agricultural University, Harbin 150030, China.
College of Food Science, Northeast Agricultural University, Harbin 150030, China.
Int J Biol Macromol. 2025 Mar;295:139625. doi: 10.1016/j.ijbiomac.2025.139625. Epub 2025 Jan 8.
This study investigates the effects of varying heat stress temperatures (56 °C to 76 °C) on the gel characteristics of egg white protein. The results indicate that when the heat stress temperature exceeds 60 °C, the textural properties, water-holding capacity, and freeze-thaw stability of egg white gel (EWG) decrease to varying extents compared to untreated EWG. At 76 °C, the proportion of free water in EWG increases from 0.9 % to 1.4 %, while rigidity, as observed in rheological analysis, decreases by approximately 48.6 %. Additionally, the α-helix content in the secondary structure reduces by approximately 20.1 %, and notable changes occur in the crystalline structure, with decreased peak intensities in Ultraviolet and both intrinsic and extrinsic fluorescence spectra. Furthermore, weakened intermolecular interactions in EWG result in the formation of larger aggregates within the microstructure. These findings suggest that increased heat stress promotes protein aggregation into disordered clusters, forming a porous gel network that releases water under external forces. This explains the observed decline in texture and water-holding capacity. The study provides a theoretical basis for improving the production and processing of egg white protein products and developing future strategies to mitigate protein aggregation.
本研究调查了不同热应激温度（56°C至76°C）对蛋清蛋白凝胶特性的影响。结果表明，当热应激温度超过60°C时，与未处理的蛋清凝胶（EWG）相比，蛋清凝胶的质地特性、持水能力和冻融稳定性会有不同程度的下降。在76°C时，EWG中自由水的比例从0.9%增加到1.4%，而流变学分析显示的刚性下降了约48.6%。此外，二级结构中的α-螺旋含量减少了约20.1%，晶体结构发生显著变化，紫外光谱以及内源和外源荧光光谱的峰值强度均降低。此外，EWG中分子间相互作用减弱导致微观结构内形成更大的聚集体。这些发现表明，热应激增加会促使蛋白质聚集成无序簇，形成在外力作用下会释放水分的多孔凝胶网络。这解释了观察到的质地和持水能力下降的现象。该研究为改善蛋清蛋白产品的生产和加工以及制定减轻蛋白质聚集的未来策略提供了理论依据。
