Jafari Zahra, Goli Mohammad, Toghyani Majid
Department of Food Science and Technology, Isfahan (Khorasgan) Branch, Islamic Azad University, Isfahan 81551-39998, Iran.
Laser and Biophotonics in Biotechnologies Research Center, Isfahan (Khorasgan) Branch, Islamic Azad University, Isfahan 81551-39998, Iran.
Foods. 2022 Sep 5;11(17):2711. doi: 10.3390/foods11172711.
The effects of phosphorylation pre-treatments at 1.5, 2.5, and 3.5% levels, as well as microwave application at 200, 400, and 700 watts levels for 2 min, on the functional parameters of egg white powder obtained by the freeze dryer procedure were investigated. P1.5-M200 had the highest oil-holding capacity, emulsion stability, and emulsion activity, while P2.5-M200 had the highest foam capacity. The P2.5-M400 had the largest particle size, and P3.5-M200 had the highest degree of phosphorylation and protein solubility. On the other hand, P3.5-M200 had the highest solution viscosity by 1% (/), water-holding capacity, and foam stability, in the treatments that used phosphorylation and microwave treatment simultaneously. FTIR spectroscopy of the unfolding structure of egg white protein revealed changes in the protein's secondary structure, such as the development of β-sheets and β-turns, as well as the binding of negatively charged phosphate groups on the serine, threonine, and tyrosine side chains. The phosphorylation and microwave treatments reduced the particle size of the egg white protein powder while increasing the surface area of the protein molecules, according to SEM analyses.
研究了1.5%、2.5%和3.5%水平的磷酸化预处理，以及200瓦、400瓦和700瓦水平微波处理2分钟，对通过冷冻干燥法获得的蛋白粉功能参数的影响。P1.5-M200具有最高的持油能力、乳化稳定性和乳化活性，而P2.5-M200具有最高的泡沫容量。P2.5-M400具有最大的粒径，P3.5-M200具有最高的磷酸化程度和蛋白质溶解度。另一方面，在同时使用磷酸化和微波处理的处理中，P3.5-M200具有1%（/）的最高溶液粘度、持水能力和泡沫稳定性。蛋清蛋白展开结构的傅里叶变换红外光谱（FTIR）显示了蛋白质二级结构的变化，如β-折叠和β-转角的形成，以及丝氨酸、苏氨酸和酪氨酸侧链上带负电荷的磷酸基团的结合。根据扫描电子显微镜（SEM）分析，磷酸化和微波处理减小了蛋清蛋白粉的粒径，同时增加了蛋白质分子的表面积。
