Influence of Relative Humidity on Internal Quality, Bacterial Load, and Mold Contamination of Eggs During 28-Day Storage

Abstract

This study analyzed the effects of varying relative humidity (RH) on the internal and microbiological quality of eggs stored at ambient temperature (22±2°C) for 28 days. Medium-sized eggs, produced by 60-week-old Lohmann Brown hens (n=30), were selected randomly and allocated into sealed chambers set to 20%, 60%, or 100% RH. Egg weight s were measured weekly, while internal quality attributes were evaluated at the conclusion of the storage duration. Eggs stored at 20% RH exhibited the highest weight loss (5.9%), whereas those at 100% RH showed minimal moisture loss (0.39%). Eggs stored at 20% RH also exhibited the highest yolk redness. Compared to 96.7% and 100% in the 60% and 20% RH groups, respectively, only 36.7% of eggs stored at 100% RH remained organoleptically acceptable for consumption after 28 days, based on predefined classification criteria. The 60% RH condition resulted in the poorest albumen structure, as reflected by the lowest Haugh unit scores. The length and width of the albumen decreased at 20% RH, while yolk pH remained unaffected by the humidity level. The yolk index declined as humidity increased. Eggs stored at 100% RH harbored the highest microbial loads, including mold, yeast, and aerobic bacteria, whereas the lowest shell contamination was observed at 20% RH. No significant differences in microbial counts were identified between the 20% and 60% RH groups. In conclusion, storage at low humidity (20%) was associated with better preservation of selected quality whereas saturated humidity (100%) was associated with significant quality deterioration and an increased risk of contamination.