College of Food Science and Engineering, Collaborative Innovation Center for Modern Grain Circulation and Safety, Key Laboratory of Grains and Oils Quality Control and Processing, Nanjing University of Finance and Economics, Nanjing 210023, China.
College of Food Science and Engineering, Collaborative Innovation Center for Modern Grain Circulation and Safety, Key Laboratory of Grains and Oils Quality Control and Processing, Nanjing University of Finance and Economics, Nanjing 210023, China.
Int J Biol Macromol. 2023 Dec 31;253(Pt 1):126682. doi: 10.1016/j.ijbiomac.2023.126682. Epub 2023 Sep 2.
In this work, the effects of quinoa protein Pickering emulsion (QPPE) on protein oxidation, structure and gastrointestinal digestion property of myofibrillar protein gels (MPGs) after freeze-thaw (F-T) cycles are revealed. SDS-PAGE results indicated that 5.0 %-10.0 % QPPE addition slowed down the protein degradation. Meanwhile, 5.0 %-7.5 % QPPE maintained the stability of the protein secondary and tertiary structure of MPGs after F-T cycles. The sulfhydryl group, disulfide bond and dityrosine content increased with QPPE supplementation. The conformations of disulfide bond changed from g-g-t and t-g-t to g-g-g after F-T cycles, and 5.0 %-7.5 % QPPE stabilized the changes of t-g-t conformation. Furthermore, the increase of dityrosine content after F-T cycles was significantly reduced with 7.5 % QPPE addition, indicating its effect to slow down protein oxidation of MPGs. In addition, MPGs with 5.0 % and 7.5 % QPPE showed noticeably higher zeta potential values than other groups, indicating the enhanced electrostatic repulsion and weakened aggregation caused by F-T damage. This work showed that 7.5 % QPPE improved the F-T stability of MPGs and reduced the protein denaturation and oxidation caused by F-T treatments, exerting no side effect on the digestion property of MPGs. QPPE can be used as a green and effective antifreeze in meat industry.
在这项工作中，揭示了藜麦蛋白 Pickering 乳液（QPPE）对经过冻融（F-T）循环后的肌原纤维蛋白凝胶（MPG）的蛋白质氧化、结构和胃肠消化特性的影响。SDS-PAGE 结果表明，添加 5.0%-10.0%的 QPPE 可以减缓蛋白质的降解。同时，5.0%-7.5%的 QPPE 可以保持 MPGs 在 F-T 循环后的蛋白质二级和三级结构的稳定性。巯基、二硫键和二酪氨酸含量随着 QPPE 的添加而增加。F-T 循环后，二硫键的构象从 g-g-t 和 t-g-t 变为 g-g-g，而 5.0%-7.5%的 QPPE 稳定了 t-g-t 构象的变化。此外，F-T 循环后二酪氨酸含量的增加明显减少，添加 7.5%的 QPPE 表明其能减缓 MPGs 蛋白质氧化。此外，添加 5.0%和 7.5%QPPE 的 MPGs 的 ζ 电位值明显高于其他组，表明 F-T 损伤引起的静电排斥增强和聚集减弱。这项工作表明，7.5%的 QPPE 提高了 MPGs 的 F-T 稳定性，减少了 F-T 处理引起的蛋白质变性和氧化，对 MPGs 的消化特性没有副作用。QPPE 可以作为肉类工业中一种绿色有效的抗冻剂。
