Detection and discrimination between ochratoxin producer and non-producer strains of Penicillium nordicum on a ham-based medium using an electronic nose

Aims: To evaluate the potential use of volatile fingerprints produced by Penicillium nordicum to discriminate ochratoxin A (OTA) producers or non-producers strains on a ham-based medium. Methods and Results: Experiments were carried out on a 3% ham medium at two water activities (0.995, 0.95 aw) inoculated with P. nordicum spores and incubated at 25°C for up to 14 days. Agar discs were sampled after 1, 2, 3, 7 and 14 days, placed in 30 ml vials, sealed and the head space analysed using e-nose. The effect of environmental conditions on growth and OTA production was evaluated based on the qualitative response. PCA showed that after 72 hrs volatile fingerprints did not help discriminate between treatments, after 7 days, they were able to discriminate between strains grown at 0.995 aw and after 14 days the OTA producer and non-producer strain and the control could be discriminated at both aw. Conclusions: This study suggests that volatile fingerprints produced by P. nordicum strains may differ and be used to predict the presence of toxigenic contaminants in ham. Significance and impact of the study: This approach could be utilised in ham production as part of a quality assurance system for preventing OTA contamination.