C03039: A feasibility study for a rapid detection method of patulin in fruit juice and apple products

Study Duration: October 2003 to October 2004

Contractor: Central Science Laboratory

Apple and apple products consumed in the UK have the potential to be contaminated with patulin, a teratogenic mycotoxin. Detection and quantification of patulin levels in foodstuffs via current methods is expensive, technically demanding and slow. An alternative methodology for patulin detection and quantification that is rapid and low cost would be attractive and should lead to an increase in the extent of monitoring for patulin in apple products.

This investigation will use a microorganism to detect the patulin in an agar plate diffusion assay, selecting the most appropriate strain by screening a variety of bacteria. The sensitivity and specificity of the test will be determined, as well as assessing its fitness for testing for patulin within apple juice. The potential for developing a rapid test kit will be explored.

This research assessed the feasibility of developing a method of detecting patulin in fruit juice more rapidly than current methods. Based on an agar plate diffusion assay, various microorganisms were screened for their sensitivity towards patulin, a mycotoxin possessing antibacterial properties. Among these, the Bacillus thuringiensis LMG 12268 species was found to be the most sensitive to patulin and the most robust to the introduction of apple juice. It was anticipated that broader strain screening might highlight an improved strain. In order to develop a test kit for non-specialists, an agar test-tube format was developed, possessing thresholds of sensitivity similar to the disc test, equivalent to 10 µg/ml. This was significantly above the FSA recommended maximum levels of 0.01 - 0.05 µg/ml. A range of growth indicators (Andrade, bromocresol purple, bromothymol blue, triphenyl tetrazolium chloride, α-4-methylumbelliferyl α-D-glucoside) were tested but were not found to increase the sensitivity of either patulin tests. Unspiked apple juice samples were shown to cause inhibition of the microbes, highlighting a limitation of both tests due to them being not wholly specific for patulin.

In summary: a potentially rapid test for detecting patulin in apple juice has been investigated but found to lack the sensitivity for use in enforcement of the EU limit.

The final report is available from the Agency's Information Centre. To obtain a copy, please contact the Enquiry Desk, Information Services, Food Standards Agency (tel: 020 7276 8181/8182 or email: infocentre@foodstandards.gsi.gov.uk)

Contact: For any enquiries concerning this research project, please contact the relevant programme contact or email: science@foodstandards.gsi.gov.uk