Mycotoxin migration in jam samples: a study on natural contamination and experimental inoculation

Due to limited control at the household level, secondary metabolites of moulds, such as mycotoxins, are primarily ingested in domestic settings. This is because some people commonly remove only the visibly mouldy portions of spoiled food and consume the remaining parts, which may still contain significant levels of these partly toxic compounds. From a food safety perspective, this raises the questions of how far these secondary metabolites diffuse into the food and how toxic they are for humans. To investigate these issues, 57 jars of mouldy jam were collected from Austrian producers. The dominant contaminating fungal species were tentatively identified as Penicillium cf. crustosum , Penicillium cf. bialowiezense , and Aspergillus cf. niger . LC-MS/MS analysis of toxin extracts of these jams revealed that 1 cm below the mycelium most secondary metabolites were reduced by ≥80%, with the exceptions of atlantinon A, nigragillin, mycophenolic acid, and roquefortine D. Subsequently, apricot roaster jam was inoculated with spores of P . cf. crustosum , P . cf. bialowiezense , and A . cf. niger and incubated for 14 days at room temperature. Secondary metabolites were again analysed, demonstrating a significant reduction in their concentration in layers beneath the mycelium. In jam samples taken 1-2 cm below the mycelium most secondary metabolites were reduced by ≥96%, except for andrastin A, quinolactacin A, and viridicatol. However, the migration of metabolites depends on the composition of the jam, including factors such as water activity and sugar content, the inoculated fungal strains, and the incubation time and temperature. This study focused on a short incubation period and only three different fungal strains.