Pharmaceutica Analytica Acta

Abstract

Aflatoxins in Walnut (Juglans regia L.), Pecan (Carya illinoinensis (Wangenh.) K. Koch) and Cashew (Anacardium occidentale L.) Nuts of Mexico

José Adaya-González, Magda Carvajal-Moreno, Francisco Rojo-Callejas and Silvia Ruiz-Velasco

Aflatoxins (AF) are toxic and carcinogenic secondary metabolites produced by Aspergillus molds, in oilseeds. Objective: To identify and quantify AF (AFB1, AFB2, AFG1 and AFG2) in walnuts, pecans and cashews consumed in Mexico using a validated method. Methods: The nut sampling was conducted in the three main markets of the 16 boroughs of Mexico City. The samples were homogenized, the extraction method was validated, and the concentrations of the 4 AF were determined by immunoaffinity columns. The identification and quantification of the AF was carried out by high performance liquid chromatography. A statistical analysis included the Wilcoxon/Kruskal-Wallis test to compare the variation of the origin of samples, types of AF and nut. Results: The recovery percentages of the AF ranged from 75% to 95%. The limits of detection (LOD) of the AF (ng/g), based on the calibration curves, were: 0.1 (AFB1), 0.01 (AFB2), 0.01 (AFG1) and 0.05 (AFG2). Of the 50 samples analyzed, 22% were contaminated with AFB1, and 100% were contaminated with AFt. The average concentrations of AF in the walnut were 0.05 ng/g of AFB1 and 2.10 ng/g of AFt. For the pecan, the concentrations were 0.09 ng/g of AFB1 and 0.44 ng/g AFt, and for the cashew, 0.02 ng/g of AFB1 and 1.36 ng/g AFt. The walnut was the most significantly (p<0.05) contaminated by AFB1, AFB2, AFG1, AFG2 and AFt, and the most contaminated boroughs with AFB1 were Tlalpan (0.23 ng/g) and Coyoacan (0.26 ng/g). For the pecan and cashew, no significant difference was found between the boroughs in AFB1 and AFt contamination. Conclusion: Aflatoxins are potent mutagens and proven carcinogens, Type I for humans that should be prevented to warranty the quality of oilseeds, nuts are a source of carcinogen ingestion and their consumption can be a risk to human health.