Wang Zhaoxin, Zhao Haibo, Tao Haiteng, Yu Bin, Cui Bo, Wang Yan
College of Food Science and Engineering, Qilu University of Technology, Shandong Academy of Sciences, Jinan, Shandong, China.
State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, Jinan, Shandong, China.
Front Nutr. 2023 Apr 11;10:1140737. doi: 10.3389/fnut.2023.1140737. eCollection 2023.
Whey protein microgel (WPM) is an emerging multifunctional protein particle and methods to improve its functional properties are continuously being explored. We developed a method to prepare WPM by heat-induced self-assembly under different ultrasound power (160, 320, 480, and 640 W/cm) and characterized the particle size, surface hydrophobicity, disulfide bond, viscosity, and foam properties of WPM. Ultrasound increased the particle size of WPM-160 W to 31 μm. However, the increase in ultrasound power gradually reduced the average particle size of samples. The intrinsic fluorescence spectrum showed that ultrasound unfolded the structure of whey protein and exposed more hydrophobic groups, which increased the surface hydrophobicity of WPM. In addition, infrared spectroscopy suggested ultrasound decreased the α-helix content of WPM, implying an increase in the flexibility of protein molecules. The disulfide bond of WPM was broken by ultrasound, and the content of the-SH group increased correspondingly. The rheology indicated that the apparent viscosity decreased with the increase of ultrasonic power. Compared with the control, the ultrasonicated WPM displayed higher foam ability. Ultrasound improved the foam stability of WPM-160 W but destroyed the foam stability of other samples. These results suggest that proper ultrasound treatment can improve the physicochemical and foam properties of WPM.
乳清蛋白微凝胶（WPM）是一种新兴的多功能蛋白质颗粒，人们一直在不断探索改善其功能特性的方法。我们开发了一种在不同超声功率（160、320、480和640 W/cm）下通过热诱导自组装制备WPM的方法，并对WPM的粒径、表面疏水性、二硫键、粘度和泡沫特性进行了表征。超声使WPM-160 W的粒径增大至31 μm。然而，超声功率的增加逐渐降低了样品的平均粒径。内源荧光光谱表明，超声使乳清蛋白的结构展开，暴露出更多疏水基团，这增加了WPM的表面疏水性。此外，红外光谱表明超声降低了WPM的α-螺旋含量，这意味着蛋白质分子的柔韧性增加。WPM的二硫键被超声破坏，-SH基团的含量相应增加。流变学表明，表观粘度随超声功率的增加而降低。与对照组相比，经超声处理的WPM表现出更高的发泡能力。超声改善了WPM-160 W的泡沫稳定性，但破坏了其他样品的泡沫稳定性。这些结果表明，适当的超声处理可以改善WPM的物理化学和泡沫特性。
