Investigation of quality properties of chicken eggs collected periodically from different poultry systems depending on the season

Abstract

In the present study, changes in the quality characteristics of the albumin and yolk parts of the eggs obtained from different poultry systems for four seasons were investigated. The highest egg weight, shell thickness, dry shell weight, shell deformation, shell fracture, and vitellin membrane strength values were determined to be in cage systems with 70.92 g, 0.45 mm, 9.46 g, 0.79 mm, 71.80 N, and 0.13 N, respectively. L* values of the white and yolk parts increased in the transition between seasons (spring-winter). The highest Salmonella spp. and Escherichia coli counts were determined in backyard poultry in winter with 9% and 5% in the albumin, and 6% and 4% in yolk parts, respectively. The highest Listeria spp. count was determined in the eggs obtained from backyard system in summer (2% in white part and 6% in yolk part). Only 5 out of 1,200 eggs collected were positive for Campylobacter spp. Novelty impact statement The highest microbial counts of the white and yolk parts of the eggs were obtained from backyard poultry in summer whereas the lowest counts were determined in samples obtained from cage systems in winter. The samples obtained from the cage and free-range systems, especially in the winter season, had superior quality compared to those obtained from the village type poultry. The quality of the eggs obtained in the winter months was higher than those obtained in the summer months.