Impact of misuse of antimicrobial agents on egg bitterness

A hundred raw eggs samples randomly selected from Aswan university residence restaurant due to students' complain of bitter taste presence in the table eggs served to them during breakfast. The samples were examined physically and chemically for antibiotic residues and vitamins A, D3 levels concentration by Spectrophotometer. The result showed that all interior egg quality traits were normal except the presence of small blood spots in 5 eggs yolk, bitter taste were present in 18 eggs yolk, antimicrobial residues were detected in 19  eggs yolk and 4 eggs white. Antimicrobial residues positive samples were examined quantitatively by HPLC for Doxycycline (DC) residues presence. The results showed that 100% of examined samples having DC residues with means concentrations of 35±1.46 and 97±4.46 ppb for eggs white and yolk respectively. The mean levels of vitamin A and D3 in eggs yolk were 447±5.49 µg/100g and11±1.35 µg/100g respectively. The paper concludes that the high concentrations of Vitamins and Doxycycline may be the cause of bitter taste of egg.