Detection of Penicillium-Toxins in Nuts Commercialized in Italy Through LC-MS/MS Analyses

The consumption of nuts is widespread globally and constitutes a significant component of the human diet due to its nutritional value. However, the presence of mycotoxins in food products, including nuts, is a global public health concern. Mycotoxins are toxic metabolites produced by contaminating fungi such as Aspergillus spp. and Penicillium spp., which can contaminate crops during growth, harvesting, storage, or transport. The aim of this study was to conduct monitoring for the presence of mycotoxins in nuts already on the market. Specifically, secondary metabolites produced by Penicillium spp., including ochratoxin A, patulin, citrinin, cyclopiazonic acid, citreoviridin, griseofulvin, meleagrin, mycophenolic acid, penitrem A, roquefortine C, penicillins G and V, sulochrin, andrastin A, asterriquinone, chaetoglobosin A, cyclopenin, cyclopenol, and viridicatin, were investigated. Commercial products were purchased from various retail outlets in different formats, origins, and cultivation methods to assess potential influences of these factors on mycotoxin presence. Regarding Penicillium-toxins, 37% of the samples showed the presence of at least one of them, and 9% showed the simultaneous presence of two or more Penicillium-toxins. Peanuts had the highest incidence of Penicillium-toxin contamination, with at least one metabolite detected in 60% of the analyzed samples. The most common secondary metabolite among the samples was patulin (14%), while the secondary metabolite with the highest concentration was viridicatin in a walnut sample (151.40 ± 64.30 µg/kg). Besides Penicillium-toxins, aflatoxins were also analyzed with another validated LC-MS/MS method, but they were not detected in any sample. Although most Penicillium-toxins, and in particular patulin in nuts, are not currently regulated in the international legislation, they exert toxic effects on humans and animals, and their occurrence can represent a food safety risk.