College of Food Science and Engineering, Nanjing University of Finance and Economics/Collaborative Innovation Center for Modern Grain Circulation and Safety, Nanjing 210023, China.
School of Chinese Medicine, School of Integrated Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing 210000, China.
Ultrason Sonochem. 2023 Aug;98:106479. doi: 10.1016/j.ultsonch.2023.106479. Epub 2023 Jun 14.
The effect of ultrasonic treatment on emulsifying properties of wheat germ protein (WGP) was studied in this paper. WGP was subjected to low frequency (20 kHz), high intensity ultrasonic treatment at different power (200, 400, 600, 800 W) for 10 min, or different time (2, 4, 6, 8, 10, 15, 20 min) at 400 W. The emulsifying activity index and emulsion stability index of WGP were significantly improved, and the emulsion droplet was smaller and more uniform after ultrasound treatment. Ultrasound increased the adsorbed WGP concentration at the oil-water interface and reduced the interfacial tension, which explained the improved emulsifying properties of WGP. The investigation on molecular properties and protein conformation showed that ultrasound processing increased solubility, but decreased particle size and surface charge of WGP. Ultrasound processing resulted in the unfolding of the protein molecular structure indicated by the increase of surface hydrophobicity and surface free sulfhydryl group levels, and the decrease of intrinsic fluorescence intensity. Correlation analysis showed that the changes in WGP solubility, particle size, and surface hydrophobicity were the main driven factors for the improved emulsifying properties of WGP.
本文研究了超声处理对小麦胚芽蛋白（WGP）乳化性能的影响。WGP 经低频（20 kHz）、高强度超声处理，在不同功率（200、400、600、800 W）下处理 10 min，或在 400 W 下处理不同时间（2、4、6、8、10、15、20 min）。WGP 的乳化活性指数和乳化稳定性指数显著提高，超声处理后乳液液滴更小且更均匀。超声增加了 WGP 在油水界面的吸附浓度，降低了界面张力，这解释了 WGP 乳化性能的提高。对分子性质和蛋白质构象的研究表明，超声处理增加了 WGP 的溶解度，但降低了其粒径和表面电荷。超声处理导致蛋白质分子结构展开，表面疏水性和表面游离巯基水平增加，内源荧光强度降低。相关分析表明，WGP 溶解度、粒径和表面疏水性的变化是 WGP 乳化性能提高的主要驱动因素。
