Resumen de Effect of Different Heat Treatments on In VitroDigestion of Egg White Proteins and Identification of Bioactive Peptides in Digested Products
Xuefeng Wang, Ning Qiu, Yaping Liu
Chicken eggs are ingested by people after a series of processes, but to date, only a few studies have explored the nutrient variations caused by different heat treatments. In this work, the impacts of different heat treatments (4, 56, 65, and 100 °C on the in vitrodigestibility of egg white proteins were investigated by hydrolysis with pepsin or pepsin + pancreatin to simulate human gastrointestinal digestion, and the digested products were identified using Nano‐LC‐ESI‐MS/MS. Egg white proteins treated at 65 °C had the highest in vitropepsin digestibility value whereas the pepsin + pancreatin digestibility increased significantly (P< 0.05) as the cooking temperature was raised. The molecular weight distribution of the digested products indicated that, when compared to pepsin‐treated samples, pepsin + pancreatin‐treated samples contained more low‐molecular‐weight peptides (m/z < 849.2) with higher signal intensities. The number of unique peptides identified in every digestion product showed a positive correlation with their in vitrodigestibility. Additionally, bioactive peptides such as antioxidant, antimicrobial and antihypertensive peptides were found present in egg white digested products, especially in samples treated at 4 and 100 °C. These findings may facilitate a better understanding of nutritive values of egg white proteins and their digested products under different cooking temperatures, such as antibacterial and antioxidant peptides identified in the digestion samples treated, respectively at 4 and 100 °C. This study also provided information for improving the applications of eggs in the food industry as well as a theoretical basis for egg consumption.
