Simultaneous residue analysis of antibiotics in food

The dairy sector is a major and highly technologically advanced industry characterized by intense competition and strong price pressure. High-performance dairy cows (producing up to 60 liters of milk per day) are often treated prophylactically with antibiotic (AB) combination preparations in cases of udder infections (mastitis) or before calving, during which time they are removed from milk production.

The use of (reserve) antibiotics poses a problem, as these can accumulate in milk and promote antibiotic resistance—a critical issue within the One Health framework. If the amount of antibiotics in milk exceeds the maximum residue limits set by the Raw Milk Quality Regulation, the milk cannot be marketed.

Currently available rapid test methods for detecting antibiotics are unable to ensure reliable identification or quantification of individual antibiotics. Accurate determination of contamination levels is presently only possible through trained personnel in well-equipped laboratories, which is associated with high costs.

The project aims to develop a rapid and easy on-site detection method for antibiotic (AB) residues in milk based on competitive magnetic immunodetection. The goal is to enable simultaneous (multiplex) quantitative detection of the most important antibiotics within less than one hour.

Preliminary studies have already demonstrated that quantitative detection of penicillin and kanamycin in milk is possible below or around the threshold values specified in the Raw Milk Quality Regulation (Pietschmann et al., 2020). This will allow even untrained users, such as dairy farmers, to reliably assess whether a milk sample—from an individual animal or a bulk tank—poses a potential risk for further processing or the food chain.

The on-site detection system is intended for use by dairy farmers, dairies, food inspectors, and accredited testing laboratories. It aims to minimize financial losses for producers while simultaneously enhancing food safety.