Effect of roasting on degradation of Aflatoxins in contaminated pistachio nuts

Abstract

With increasing knowledge and awareness of aflatoxins (AFs) as potent sources of health hazards to both human and animals, a great deal of effort has been made to completely eliminate the toxin or reduce its content in foods. Although prevention is the most effective intervention, heat has been used to inactivate AFs in contaminated foodstuff. Nuts as general and especially pistachio nuts are very sensitive commodity to AFs contamination. In this study effect of roasting on reduction of AFs content in pistachio nuts has been tested in a laboratory setting with aiming to suggest an optimal condition for the roasting. Although all treatment protocols showed some degree of AFs degradation (ranging from 17% to 63%), roasting spiked samples at 120 °C for 120 min and 150 °C for 30–120 min caused substantial reduction of AFs in samples. Treatment of naturally contaminated whole pistachio kernels at 150 °C for 30 min significantly reduced level of AFs contamination in samples. Degradation of AFs was both time and temperature dependent. Roasting at 150 °C and 120 min condition degraded more than 95% of AFB1 in pistachio. However, the resulted product was not edible. AFs in form of naturally occurrence were more resistant to degradation with heat.