Md. Mehedi Hasan Patwary¹, Tania Rahman¹, MM Towhidul Islam², Hossain Uddin Shekhar^2,

Aflatoxin is a potent carcinogen, occurring from mold growth that contaminates raw agricultural commodities, mostly staple grains. The study was conducted to elucidate the present status of aflatoxin contamination in five commonly consumed foods including rice, wheat, maize, peanut and chickpea in Dhaka city of Bangladesh. The contaminated samples were analysed by HPLC for total aflatoxin (B1, B2, G1, G2). The average percentages of aflatoxin were: maize (90%)> peanut (70%)> chickpea (60%)> wheat (50%)> rice (30%). A high incidence (90%) and concentration of aflatoxin (mean 33.2 µg/kg) was found in maize. The mean concentrations of aflatoxin in 60% chickpea, 50% wheat and 70% peanut were higher than the safe limits proposed by FDA (20 µg/kg). Rice had comparatively lower concentrations (mean 15.4 µg/kg) of aflatoxin of which 30% were beyond safe limits. For detoxification, the samples were treated in either 1% or 5% calcium hydroxide. The 5% calcium hydroxide treatment reduced more toxin than that of 1%. A quantum chemical calculation was done to address the chemical binding of aflatoxin with blood electrolytes. Cationic electrolytes i.e., (Na⁺,  K⁺, Ca²⁺ and Mg²⁺ bound to the O₁₈-O₂₂ position of the aflatoxin B1. The divalent cations (Ca2+, Mg2+) bound more strongly to AFB1 than the monovalent cations (Na+, K+). According to the descending order their binding strength was: Mg2+ (-224.5 kcal) > Ca2+ (-156.6 kcal) > Na+ (-67.1 kcal) > K+ (-37.3 kcal). This study gave us an insight about the potential risks of aflatoxin to public health.

aflatoxin, detoxification, electrolyte imbalance, electrolyte binding strength