Enrofloxacin and Ciprofloxacin Residues in Table Eggs: Distribution and Heat Treatment Effect

A 500 composite egg samples (2500 eggs-each sample represented by 5 eggs) collected from layer farms and local markets from all over Jordan were studied for presence of antimicrobials using Premi®Test screening test. Positive samples indicated by inhibition of microbial growth represented 12.8% out of total screened egg samples. Positive samples were examined quantitatively using HPLC technique to detect the presence of enrofloxacin and ciprofloxacin. Ciprofloxacin and enrofloxacin residues were detected in 1% and 0.8% of the total samples, respectively, where both drugs were recovered from white but not yolk. The effect of boiling on either drugs concentration in fortified white or yolk was demonstrated by gradual increases in the mean reduction percentages within treatment time with an average of 87% reduction after 15 minutes of boiling for both drugs and egg compartments and 5 minutes of frying at 160°C. The average concentration reduction percentages by the end of four weeks of refrigeration of fortified yolk and white were around 45 and 50% for enrofloxacin and ciprofloxacin respectively. The significance and mechanism of drug deposition and reduction during processing is being highlighted.