Removal of aflatoxin B1 by roasting with lemon juice and/or citric acid in contaminated pistachio nuts

Nowadays, aflatoxin B1 (AFB1) could be considered as one of the most hazardous mycotoxins for humans, and nuts comprise one of the major responsible food categories for human exposure to this mycotoxin. Thus, complete elimination of AFB1 or reduction of its content in nut foods, such as pistachio attracted lots of attentions. In the current study, the efficacy of roasting process by incorporation of lemon juice and/or citric acid on the reduction of AFB1 in contaminated pistachio nuts (AFB1 at two levels of 268 and 383 ng/g) was investigated. Significant degradation of AFB1 (up 93.1% for AFB1) was recorded by applied treatment protocols. Although roasting of 50 g pistachio nuts with 30 ml water, 30 ml lemon juice and 6 g of citric acid at 120 °C for 1 h resulted to a significant degradation (93.1 ± 8.2%) of AFB1, this treatment altered the desired physical properties. Roasting with 30 ml water, 15 ml lemon juice and 2.25 g of citric acid at 120 °C for 1 h reduced the level of AFB1 in 49.2 ± 3.5% of the initial level without a noticeable change in desired appearance of pistachios. Hence, a synergistic effect between heating and lemon juice/citric acid in order to AFB1 degradation was observed. It could be concluded that roasting process with lemon juice and citric acid could be applied as a useful and safe degradation method of AFB1 in naturally contaminated pistachio nuts.