Mycotoxin Contaminants of Walnuts-Preliminary Studies

Mycotoxins are important indicators of product quality. They show various levels of toxicity, and contaminated food can cause acute, sub-acute, or chronic food poisoning and exert a negative effect on human health. The aim of the study was to determine the concentration of selected mycotoxins: total aflatoxins, aflatoxin B1, ochratoxin A, fumonisin, T-2/HT-2 toxins, and zearalenone in walnuts collected in private household gardens in Lublin Province. Walnut (in shells) were collected in June/July 2020. The material, i.e. 38 walnut samples from autumn harvest in 2019, was donated for the analyses voluntarily. Quantitative tests ELISA were used to detect the presence of mycotoxins in the edible part of the nuts. Over 86% of the walnut samples were found to exceed the maximum residue levels for the total aflatoxin concentration (4 mu g/kg) for tree nuts intended for human consumption or used as an ingredient in food products. The concentration of aflatoxin B1 exceeded the allowable level of 2 mu g/kg in over 65% of the samples. In addition to aflatoxins, two other mycotoxins (ochratoxin A and T-2/HT-2) were detected in over 28% of the samples, three compounds (ochratoxin A, fumonisin, and T-2/HT-2) - in 15.8% of the samples, and ochratoxin A, T-2/HT-2, and zearalenone were contained in 10.5% of the samples. Aflatoxin is the most common fungal contaminant of walnuts however other mycotoxins, may be identified in this product as well. Potentially they all exert an unfavorable impact on consumer health..

Automated summary

Mycotoxins are important indicators of product quality and can negatively affect human health. This study investigated the concentration of mycotoxins in walnuts collected from private household gardens in Lublin Province. The results showed that a high percentage of the samples exceeded the maximum residue levels for total aflatoxin concentration and aflatoxin B1 concentration.