Physical and chemical quality of sanitized commercial eggs experimentally contaminated with Pseudomonas aeruginosa and refrigerated during storage

The objective of this study to verify the physicochemical quality of commercial washed and unwashed eggs, experimentally inoculated on the shell with Pseudomonas aeruginosa and stored at 5 and 25 ºC for 30 days. A total of 384 eggs, classified as large, from light Dekalb White laying hens at 30 to 40 weeks of age, were used. The experimental design consisted of two blocks in a 2 × 2 × 2 factorial arrangement (contamination, washing, and refrigeration) with six replicates. The sanitization was performed by mechanical washing (hot water with chlorhexidine 20% and 8% active content). Eggs were contaminated by handling with 1.5 × 10(5) colony-forming units (cfu) of Pseudomonas aeruginosa/mL solution, and stored at 5 and 25 ºC for 30 days. Each ten days, analyses of the eggs were carried out, for the assessment of physical (egg weight, specific gravity, shell thickness, yolk, albumen and shell percentage, Haugh unit, yolk and albumen rates) and chemical (albumen and yolk pH) characteristics. There were interactions between sanitization, storage temperature and contamination. The cooling process maintained the egg internal quality even when there was contamination on the shell by Pseudomonas aeruginosa inoculum. Cooling slows down the weight loss and promotes better internal physical and chemical quality of the eggs during the 30 days of storage regardless of the contamination and washing processes.