Occurrence of Alternaria mycotoxins and aflatoxins contamination in vegetable oils by enzyme immunoassay study

Abstract Vegetable oils constitute a significant component of the human diet. The oilseeds utilized for their production are susceptible to contamination by mycotoxins (MTs) during cultivation and storage, particularly under suboptimal conditions. The extent and nature of fungal invasion leading to MT contamination also depends on the geographical origin of oilseed production. This study sought to investigate the prevalence of aflatoxins (AFs), alternariol (AOH), and tenuazonic acid (TEA) contamination in 18 types of edible vegetable oils using appropriate enzyme-linked immunosorbent assays (ELISAs). The oils examined ( n = 102) included common types such as sunflower, linseed, olive, mustard, sesame, hemp, and some others from the domestic market. The detection limits of the established assays were found to be consistent with the regulatory limits: 5, 10, and 100 μg/kg for AFs, AOH, and TEA, respectively. To ensure a satisfactory recovery of the analytes from the oil matrix, individual extraction solvents were necessary for AFB 1 , AOH, and TEA. The recovery ranges of MTs from a wide range of common edible oils were found to be 68.8–99.8%, 63.9–114.1%, and 70.6–115.9%, respectively, with variation coeffecients of less than 19%. The ELISA detection limits of 0.003, 0.02, and 0.15 ng/mL provided high detectability of AFB 1 and AOH (73.5%), and TEA (66.6%) in the studied oils. However, their content above the maximum residue limits (MRLs) was observed only in 0, 4.9%, and 7.8% of the samples, respectively. The examination showed a notable decrease in the incidence and residual levels of AFs, AOH, and TEA in the refined sunflower oils compared to the unrefined oils. This study offers insights into the occurrence and MT contamination of vegetable oils within the Russian region and validates the efficacy of ELISA, in conjunction with optimized extraction protocols, for the routine analysis of a broad spectrum of oil types.