Aflatoxin B1 values and mycological contamination of dog diets containing insects as protein sources

Abstract

The main objective of the paper is to evaluate the risks of mycological contamination as well as the level of Aflatoxin B1 of dogs feeds containing insects as a source of protein (e.g. Hermetia illucens). A number of 12 fodder samples were collected, representing 10 animal feedstuffs collected from different pet shops, a dry insect larvae and a fresh insect sample Black soldier fly (BSF). The mycological examinations of analyzed samples were carried out by insemination on Sabouraud sterile medium, two per each dilution. The total fungi count was assessed and identified the genera using a binocular magnifier. The results were expressed in CFU/g product. Identification of prevailing fungi was carried out by stereomicroscopic examination of the cultural characters of colonies and microscopic preparations on slides, stained with Bleu Cotton. The quantitative identification of the Aflatoxin B1 from feedstuffs and insect samples was performed by means of ELISA using a commercial available kit. RIDASCREEN® FAST Aflatoxin - a competitive enzyme immunoassay. The obtained results highlight a medium and high intensity contamination with fungi of 90% of the analyzed samples, contamination ranging from 22x103 CFU/g to 755x103 CFU/g. The fungi observed through the analysis of cultural aspects belong to genera: Penicillium spp., Aspergillus spp., Fusarium spp., Mucor spp. and Rhizopus spp. All the analyzed samples were contaminated with Aflatoxin B1 with values between 1.8 and 4.61μg/kg, levels which, however, do not exceed the maximum limits allowed by the European Community legislation. The samples of insects species Hermetia illucens contained Aflatoxin B1 in the range of 3,45 -3,51 μg/kg.