Monitoring antimicrobial residues in table eggs in Aswan governorate markets and their impact on egg quality and public health

Abstract

Background: Organic egg is among the most common organic foods offered for sale in Egyptian markets in recent years, and consumers buy them at a higher price because they believe organic eggs are safer and have superior nutritional value than conventional eggs. Aim: The present work aimed to monitor antimicrobial residues in brown table eggs, whether conventional or organic type, in Aswan governorate markets and assessed their physical and chemical quality and their public health hazards. Methods: Brown table egg samples (n=400 total) were randomly selected in the present study, whereas they represented two equal groups (n=200 each) including conventional eggs and organic eggs. Eggs were collected from different retail stores in Aswan governorate, Egypt. Egg samples were subjected to thorough physical and chemical quality evaluation as well as assessment of antimicrobial residues. Results: The results reported organic eggs were cleaner and had a better odor, less blood and meat spots, but smaller with more shell cracks than conventional eggs. Chemical analysis of some nutrient contents in the egg yolk revealed significantly higher nutritive values of organic eggs than that of conventional ones as the organic eggs contain significantly higher levels of vitamin A and vitamin D/D3 and significantly lower values of cholesterol, calcium, magnesium and zinc than those in conventional eggs. Disc diffusion assay has been used for monitoring antimicrobial residues in egg samples. The results have shown that all examined organic eggs were free from antimicrobial residues, while 12% and 8% of conventional egg yolk and white were positive for antimicrobial residues, respectively. Conclusion: The study concludes the higher nutritive value of organic eggs compared with the conventional type because of their significantly higher contents of vitamins A and D and their significantly lower contents of cholesterol. Moreover, organic eggs were free from antimicrobial residues which maximize their public health benefits.