Effect of Various Thermal Treatments on Erythromycin Residues and Degradation Products in Turbot Fish Meat: Implications for Food Safety

Erythromycin, a widely utilized antibiotic in aquaculture, poses potential food safety risks through residues in fish products. However, research on the effects of thermal processing on its degradation remains limited. This study developed a sensitive detection method using UHPLC-Q-Exactive HF-X to quantify erythromycin and its degradation products, investigating influences of various thermal treatments and predicting additional degradants. Turbot meat samples spiked with erythromycin were processed via roasting, microwaving, deep frying, and boiling. Post-treatment degradants were identified, with potential metabolites forecasted through structural analysis. The results indicated that erythromycin rapidly degrades under all thermal treatments, with boiling and roasting promoting substantial formation of dehydration products (anhydroerythromycin A and erythromycin A enol ether). The content of N-demethylerythromycin A remained consistently low and stable (<6.67 ng/g). Additionally, five additional erythromycin degradants were screened out. The degradation pathways and product profiles of erythromycin varied depending on the thermal treatment, indicating that thermal processing does not eliminate erythromycin residues but rather transforms them into other substances. This study revealed the specific degradation pattern of erythromycin during thermal processing of fish meat, providing scientific evidence for identifying which harmful substances require priority monitoring in processed fish products, thereby enhancing the level of food safety assessment.