Occurrence of Filamentous Fungi and Mycotoxins in Fresh and Minimally Processed Leafy Vegetables from Gardens and...

Fresh, minimally processed foods contain many valuable nutrients but are also a source of pathogenic microorganisms. This study aimed to investigate the presence of filamentous fungi and mycotoxin contamination in leafy vegetables. A total of 160 samples of lettuce, spinach, mixed salads, and sprouts from markets and gardens were tested. Fungal strains were cultured on Malt Extract Agar with chloramphenicol (50 mg/L). Fungal identification was performed by macroscopic and microscopic observations, amplification of the small subunit rRNA (SSU rRNA) gene fragment, and sequencing. Total aflatoxins, aflatoxin B1, and zearalenone contents were determined using the ELISA method. The mean concentrations of filamentous fungi in fresh and minimally processed vegetables were 9.4 × 10² CFU/g and 3.4 × 10² CFU/g, respectively. Nineteen fungal genera were identified, in addition to non-sporulating fungi, of which the largest percentage comprised the genera Cladosporium (38%), Alternaria (37%), and Fusarium (30%), and less frequently Penicillium, Mucor, Trichoderma, and Aspergillus (from 8 to 14% of positive samples). The highest percentage of samples contaminated with zearalenone was observed in the spinach group. Ready-to-eat leafy vegetables should be monitored for contamination with filamentous fungi and mycotoxins as they pose a potential risk to consumer health.