Abstract

The purpose of this study was to determine the effects of different cooking processes like boiling, roasting and microwaving on doxycline residues in chicken muscle, liver and gizzard tissues of broiler chickens. Each chick was fed by water and food with 0.1% of Doxycline in their drinking water for 5 consecutive days. Then, three locations were sampled aseptically from each carcass: Breast muscle, liver and gizzard. doxcycline residue was analysed using microbial inhibition method by plates seeded with Escherichia coli. After doing different phases of the test on raw samples, the positive raw samples were cooked by various cooking procedures and we surveyed the cooked samples with a similar method again for the detection of residue. The results showed a reduction in the concentration of doxycline residue after different cooking processes and a part of the residue in the boiling process were excreted from the tissue to the cooking fluid. Between the various agents affecting antibiotics residue after the cooking process, cooking time and temperature can play a major role in antibiotic residue reduction while cooking food. Regarding the results of this study, we can conclude that cooking processes do not guarantee a full elimination of these drugs present in condemned animals and it can only decrease its amounts.

Key words: Cooking, doxycline, residue, poultry, edible, tissue.