Evaluation of the Use of Gamma Radiation for Reduction of Aflatoxin B1 in Corn ( Zea mays) Used in the Production of Feed for Broiler Chickens

Abstract

Corn is one of the main grasses used to produce human or animal food. One of the main problems with the use of corn is the presence of mycotoxins, where aflatoxin B1 is one of the most harmful for human and animal health. Chemical methods such as the addition of antifungals and sequestrants are used to control this contaminant in food; however, these methods can leave dangerous residues. The aim of this research was to evaluate the effectiveness of irradiation with gamma rays on corn for the control of aflatoxin B1. For this purpose, three treatments were compared: treatment 1, application of gamma radiation, treatment 2, application of antifungal and treatment 3, combination of gamma radiation and application of antifungal. Corn without exposure to any control of aflatoxin was used as a witness group. Irradiation doses of 2, 6 and 10 kGy were tested, and the dose of 6 kGy was selected as the best since it lowered aflatoxin B1 more effectively. The corn analyzed in this study was stored during 45 days at 23°C, and every 15 days. We determined the concentration of aflatoxin B1, presence or absence of pathogenic microorganisms and insects, and we evaluated the physicochemical characteristics of the grain. Then, the treatments were compared and treatment 1, only irradiation with gamma rays, proved to be significantly more effective in the reduction of aflatoxin B1 and the total inhibition of the survival of the insects during the 45 days of storage which allowed better preservation of the protein. All treatments controlled the growing of pathogenic microorganisms as Salmonella and Enterobacteriacea, and kept the humidity of the grain in values lower than 13%. The cost production of a bag of 40 kg of feed was also estimated in USD 22.56; which is1.80% greater than the cost corresponding to the conventional process that uses mycotoxin sequestrants.