Mass spectrometric based analysis of whole eggs dissolved in formic acid

Food Chem. 2022 Nov 3;405(Pt A):134846. doi: 10.1016/j.foodchem.2022.134846. Online ahead of print.

Abstract

We have developed a method for complete dissolution of whole eggs in formic acid that provides a new approach to analyzing egg biomolecules. As expected from prior work with extracted lipids, phosphatidylcholine represents the most abundant 31P NMR signal. A simplified methanol/chloroform partitioning method for separating the dissolved egg solution into metabolites, lipids and protein was performed and after ultra-high mass resolution and tandem MS fragmentation analyses several phosphatidylcholine molecules containing different fatty acid chain lengths as well as number and position of double bonds was detected. The MS based proteomic analysis further revealed 6 Gallus sequences annotated as 'uncharacterized' because they show no sequence homology with any other protein found in nature and thus, may represent proteins uniquely evolved to perform functions specific to chickens. Overall, this procedure is a rapid and facile means of characterizing in a high throughput and comprehensive manner, the molecular components of whole eggs.

Keywords: (31)P NMR; Choline; Egg; Mass spectrometry; Phospholipids; Proteins.