Egg White and Yolk Protein Atlas: New Protein Insights of a Global Landmark Food

Abstract

(1) Background: The chicken egg is an animal product of great agronomic interest. The egg white and yolk constitute high-quality protein sources for humans with high digestibility and well-balanced amino acid profiles. Despite the egg white and yolk protein’s undisputed value, research to unravel their full proteome content and its properties is still ongoing. We aimed to exhaustively analyze the proteome of egg white and yolk by applying intrinsic proteomics and bioinformatics approaches in order to unravel the full protein potential of this landmark food. (2) Methods: A total of 45 freshly laid, unfertilized, chicken eggs were subjected to nanoLC-MS/MS Orbitrap analysis following a peptide pre-fractionation step. A comprehensive bioinformatics processing step was undertaken towards elucidating potential activities and roles of identified molecules. In parallel, the literature was mined concerning all reported egg white and yolk protein identifications. (3) Results: Our analysis revealed 371 and 428 new proteins, reported for the first time to be present in the egg white and yolk, respectively. From the bioactivity standpoint, egg white and yolk proteins showed high enrichment for antioxidant and anti-inflammatory processes, while exerting high relevance for the apoptosis and focal adhesion pathways. (4) Conclusions: Egg white and yolk proteins exert diverse and multifaceted properties. A total of 799 proteins were reported for the first time as being part of the egg and yolk. Our novel protein data enriched those already published in the literature and the first ever chicken egg white and yolk Protein Atlas, comprising 1392 protein entries, was generated. This dataset will provide a cornerstone reference for future studies involving egg proteins.

Advances in Understanding the Antioxidant and Antigenic Properties of Egg-Derived Peptides

“…Among all the available literature on egg white and egg yolk, Sarantidi et al [ 2 ] recently reported the highest number of proteins, 398 and 456, respectively, identified through an LC–MS/MS intrinsic design. The most abundant proteins found in egg white are ovalbumin (54.0%), followed by ovotransferrin (12.0–14.0%), ovomucoid (11.0%), ovomucin (3.5%) and lysozyme (3.4–3.5%), while few other minor proteins, such as ovoinhibitor, ovoglycoprotein, ovoflavoprotein, ovomacroglobulin (also known as ovostatin), cystatin and avidin, are present in low percentages of 0.05–1.5% [ 1 , 4 , 20 , 21 ].…”

“…Chicken eggs have an undisputedly high biological value, being a good source of various macro- and micro-nutrients. The high nutritional value of the eggs is due to the high content of proteins with an ideal amino acids profile, essential lipids, vitamins and minerals [ 1 , 2 ]. These components are not evenly distributed between the egg components: the egg yolk consists of 55.00% water, 26.70% fats, 15.50% proteins, 1.68% ash and 1.09% carbohydrates, while the egg white has significantly higher amounts of water (87.60%) and significantly lower contents of proteins (10.80%), fats (0.19%), ash (0.62%) and carbohydrates (0.85%) [ 3 ].…”

Preparation, Biological Activities, and Potential Applications of Hen Egg-Derived Peptides: A Review

“…Hen egg proteins have high digestibility and absorption rates, and are called complete proteins [ 3 ]. Proteomic analyses identified 371, 428, and more than 500 proteins in egg white, yolk, and eggshell membrane proteins, respectively [ 4 , 5 ]. Egg white proteins mainly include ovalbumin, ovotransferrin, ovomucin, ovomucoid, and lysozyme [ 6 ].…”