Patulin assessment and fungi identification in organic and conventional fruits and derived products

In this study, patulin levels in apples and tomatoes obtained in conventional and organic farms with 0 and 100% of rotten area, were determined by gas chromatography–mass spectrometry (GC–MS) to assess the influence of the production system with patulin content. Additionally, mould species were isolated and identified using classic morphological techniques and a DNA barcode system based on nrITS, β-tubulin and calmodulin genes. The most frequently isolated genera were Rhizopus, Mucor, Alternaria, Cladosporium, Botrytis, Aspergillus and Penicillium. Higher patulin levels were found in samples contaminated by Penicillium expansum. Patulin levels were not significantly different in samples obtained from the two production system (conventional and organic). Among the three studied apple varieties, Golden delicious was the most contaminated with patulin followed by Reineta. Fuji apples with 0 and 100% of rotten area did not present quantifiable patulin levels. A survey for first time realized in commercialized tomato products showed that 35.7% of the samples (10 of 28) contained patulin in levels ranging from 3.22 to 47.72 μg/kg. In apple juices, patulin levels ranged from 1.86 to 45.47 μg/kg, which is below the maximum legal requirement (50 μg/kg).