Unravelling proteome changes of chicken egg whites under carbon dioxide modified atmosphere packaging

- ITRAQ was used to assess proteome changes of egg during storage under CDMAP.
- The bioinformatic analysis of differential proteins during storage was conducted.
- Three candidate indicators of egg freshness under CDMAP were found.
- Ten differential proteins between CDMAP group and control group were found.

Unfertilized chicken eggs within 24 h of laying were chosen and stored at 25 °C and 45% humidity for 0, 20, and 40 days. The experimental group (EG) was the carbon dioxide-modified atmosphere packaging (CDMAP) group, whereas the control group (CG) contained eggs without special handling. Egg freshness indexes were measured. The proteome of the egg whites was determined by LC-MS/MS using isobaric tags for relative and absolute quantitation (iTRAQ). A total of 87 proteins were detected. The results indicated that CDMAP can control the change in protein abundance. Using a correlation analysis between the protein abundance and freshness indexes of the EG, Beta-hexosaminidase, Trypsin inhibitor ClTI-1 and Apolipoprotein D were determined to be potential predictors of egg freshness. In comparing the proteomes of the EG and CG, it was concluded that CDMAP could affect the proteins related to egg vitelline membranes, eggshell matrix and metabolic intensity to maintain egg freshness.