Detoxifying potentials of two indigenous adsorbents: imarsil and activated charcoal in the reduction of aflatoxin in vegetable oils consumed in Nigeria

Abstract

Food contamination with aflatoxin is more prevalent in tropical regions where environmental conditions such as high temperature and humidity prevail, which favour the growth of toxigenic fungiand accumulation of these toxins in food and feeds represent a major threat to human and animal health. In lieu of the previously known adsorbents, adsorption studies of Aflatoxin (AF) were performed using inexpensive, readily available and local adsorbents Imarsil and activated charcoal (AC). Fifteen edible oils were purchases from open markets in Nigeria and screened for aflatoxin using High Performance Liquid Chromatography (HPLC). Thirteen out of the fifteen vegetable oil samples were positive to aflatoxin at the following concentration(172, 123, 195, 142, 46, 107, 96, 116, 22, 33, 228, 17 and 4) ng/kg while two had no detectable AF. Atsix different concentrations (0.5, 1, 1.5, 2, 2.5 and 3%) of Imarsil and activated charcoal (AC) with contact time of 1,2 and 3 h at room temperature (37 °C), the aflatoxin-adsorbing capabilities depend on the adsorbent concentrations and contact time. Imarsil demostrated 100 % adsorption efficiency within one hour. At AF contamination rates of 96–228 ng/kg, activated charcoal was not effective while Imarsil had 100 % removal efficiency within 3 h witha significant reduction (P<0.05) observed at the highest contamination rate and adsorbent concentration. AC demonstrated very mild adsorption activity. Results from this study indicated that Industrial incorporation of Imarsilinto the oil refining process would reduce greatly the menace of aflatoxicosis. Hence, the use of Imarsilshould be encouraged.