In vitro Degradation of Aflatoxin B1in Groundnut (Arachis hypogea) Meal by Horse Radish Peroxidase

Finely powdered defatted groundnut meal was spiked with aflatoxin B1produced by Aspergillus flavus ATCC 15517. Commercial horseradish peroxidase (200 Umg-1) and partially purified peroxidase enzyme from freshly harvested radish roots having 20, 30 and 50 µ g-1of protein were made to act upon that toxin in vitro. The experiment resulted in 53, 28, 35 and 41%, conversion, respectively. The optimum enzyme concentration occurred when 10 U of enzyme dissolved in 50 mM phosphate buffer at pH 6 was mixed homogeneously with 100 g of groundnut meal to react upon 1.4 mM AFB1at 20 °C and normal pressure up to 24 h incubation period. Hydrogen peroxide in 20 mM concentration was used as an oxidizing agent in all the reactions performed. Moisture content of the reaction media was maintained at 12-15%. Calcium propionate 0.3 g/100 g of groundnut meal was used as fungistat. After enzymatic reaction, groundnut meal was tested for its toxicity on Bacillus megaterium cells. Toxicity tests resulted in 20, 30, 44 and 63% growth inhibition of bacilli when 200, 50 and 30 and 20 Umg-1enzyme treated groundnut meal extracts were used for the reaction, respectively.