Jiangxi Key Laboratory of Natural Products and Functional Foods, College of Food Science and Engineering, Jiangxi Agricultural University, Nanchang 330045, China.
Sericultural & Agri-Food Research Institute, Guangdong Academy of Agricultural Sciences/Key Laboratory of Functional Foods, Ministry of Agriculture and Rural Affairs/Guangdong Key Laboratory of Agricultural Product Processing, Guangzhou 510610, China.
Food Res Int. 2023 Oct;172:113097. doi: 10.1016/j.foodres.2023.113097. Epub 2023 Jun 10.
This study aimed to elucidate the mechanism of acid-induced gelation in egg-based yoghurt by investigating the dynamic changes in physicochemical properties, texture, rheology, and microstructure of the gel during fermentation, combined with the role of intermolecular forces in gel formation. Results showed that protein aggregation and cross-linking increased as pH decreased during fermentation. Gel hardness increased with fermentation, eventually reaching 11.36 g, while maintaining low fracturability. Water holding capacity (WHC) decreased from 91.77% to 73.13% during fermentation. Rheological testing demonstrated a significant increase in viscosity and dynamic moduli (G' and G''), consistent with the observation of a more compact microstructure by scanning electron microscopy (SEM) and particle size analysis. Furthermore, dynamic changes of surface hydrophobicity, sulfhydryl content, and intermolecular forces suggested that hydrophobic interactions were likely the main driving force for gel formation, as well as that hydrophobic interactions and disulfide bonds played an important role in the maintenance and construction of the gel network structure. Although ionic bonds and hydrogen bonds also had an effect on the gel formation of egg-based yoghurt, their contributions were not significant. The study provided new insights for the development of novel egg-based fermentation foods and the research of acid-induced protein gels, and also contributed to the deep exploitation and utilization of poultry eggs.
本研究旨在通过考察发酵过程中凝胶理化性质、质构、流变学和微观结构的动态变化，并结合分子间作用力在凝胶形成中的作用，阐明基于鸡蛋的酸奶酸诱导凝胶的机制。结果表明，在发酵过程中，随着 pH 值的降低，蛋白质聚集和交联增加。凝胶硬度随发酵而增加，最终达到 11.36g，同时保持低易碎性。水保持能力（WHC）在发酵过程中从 91.77%下降到 73.13%。流变学测试表明，粘度和动态模量（G'和 G"）显著增加，这与扫描电子显微镜（SEM）和粒径分析观察到的更紧凑的微观结构一致。此外，表面疏水性、巯基含量和分子间作用力的动态变化表明，疏水相互作用可能是凝胶形成的主要驱动力，并且疏水相互作用和二硫键在凝胶网络结构的维持和构建中发挥重要作用。尽管离子键和氢键对基于鸡蛋的酸奶的凝胶形成也有影响，但它们的贡献并不显著。该研究为新型基于鸡蛋的发酵食品的开发和酸诱导蛋白质凝胶的研究提供了新的见解，也为家禽鸡蛋的深度开发和利用做出了贡献。
