Development and Validation of a Rapid Qualitative Test Kit for Detection of Horse Meat Residues

Introduction: A recent European investigation into meat adulteration revealed that many foods advertised as containing beef were found to contain undeclared horse meat.  Whereas consumption of horse meat is not inherently harmful, introduction of undeclared horse meat into the food supply chain significantly increases the risk of human exposure to deleterious veterinary drugs and calls into question the safety practices of several major food manufactures. In addition, consumption of horse meat in the UK and USA is verboten, as underscored by the public response that ensued following the disclosure of this scandal.

Purpose: To develop and validate a highly specific detection kit that can rapidly identify horse meat residues down to 0.01% contamination in xenogenic raw meat sources.

Methods: Polyclonal antibodies against horse serum albumin (HSA) were raised in goats and purified on an HSA-affinity column. The purified antibodies were used to develop a lateral flow immunochromatographic assay configured with a procedural control line, a test line, and an overload line. A sample extraction buffer and a running buffer were developed for optimal performance. The ensuing kit and test method were validated for specificity and dynamic range. Method concordance was assessed using a commercial ELISA (ELISA-TEK) kit and an authentication PCR-based method (IEH).

Results: The MEI/IEH horse meat lateral flow test demonstrated a range of detection of 0.01% to 100% spiked horse meat (raw or cooked into beef meat). Specificity analysis revealed no cross-reactivity with serum albumins or meats derived from chicken, turkey, pork, beef, lamb, and goat. The assay was more sensitive than the commercial ELISA kit and required considerably less time to perform than the PCR and ELISA methods.

Significance: The development of a highly specific test method capable of detecting trace amounts of horse meat in 30 min should aid Food Safety Authorities in their continued efforts to monitor for horse meat adulteration.