Impact of different processing methods on retention of oxytetracycline residues in treated tilapia

Abstract

Antibiotics used in aquaculture results in deposition of residues in muscle and other tissues of aquaculture species if withdrawal time is not given after administration of drug. Oxytetracycline (OTC) is a primary antibiotic used in the aquaculture industry for the treatment against bacterial pathogen or as prophylactic measure. The antibiotic is usually administered in a form of medicated feed. Antibiotic residues are used to be measured on uncooked tissue. Data on the effect of cooking procedures on antibiotic residues in fish are limited. In the present study the effect of different processing methods like boiling, microwave cooking, frying and drying on retention of OTC residues in treated Tilapia was investigated. OTC residues are considered relatively unstable compounds. Temperature during cooking has the largest impact on the loss of OTC residues, the more cooking time; the greater will be the loss of residues. The fish was treated with 3 different concentrations of OTC for ten days and harvested after 12h of last feeding. OTC residues retained after different processing methods was determined by LC-MS/MS.