Use of Delvotest T for Quantitative Estimation of β-lactam Antibiotic Residues in Waste Milk and for Evaluation of Thermal Treatment Efficiency – a Methodical Pilot Study
Estonian University of Life Sciences, Institute of Veterinary Medicine and Animal Sciences, Department of Food Sciences, Kreutzwaldi ⁵⁶/⁵, EE⁵¹0¹⁴ Tartu, Estonia; *Correspondence: firstname.lastname@example.org
The aim of this work was to study possibilities of using microbiological broad-spectrum inhibitor test (Delvotest T) for express estimation of antibiotic residues in bovine milk. For quantitative estimation the waste-milk samples were stepwise diluted (dilution array) by antibiotic-free milk until negative test result was achieved. Another objective was to evaluate heat treatment efficiency of waste-milk in order to degrade antibiotic residues in it. Heat treatment (in water bath) at ⁹0°C was chosen according to references in literature. In order to study certain drug residue the waste-milk samples were collected at the next milking after medical treatment. Two different drugs were investigated: Carepen and Norocillin. Preliminary results indicated that the average concentration of antibiotic residue (active substance of drugs) exceeded European MRL (Maximum Residue Limit) ⁴,¹00 (± ²,⁴0⁸) and ¹³.0 (± ⁵.⁷) times respectively. The average heat treatment duration at ⁹0°C (until negative test result of Delvotest T) was ¹⁵.0 (± ⁵.0) and ⁷.⁸ (± ¹.⁵) hours respectively.