Aflatoxin contamination and mineral profile of almond seeds

Samples of almond (Prunus amygdalus L.) seeds belonging to Pakistan, Afghanistan and Iran were incubated at 30 °C for fungal count. Bleach disinfected samples were inoculated with Aspergillus flavus, isolated from local peanut samples, to assess them for aflatoxins B1, B2, G1, and G2 by HPLC and change in proximate and mineral contents. Aflatoxins content in inoculated samples indicated the presence of B1 (21.3 to 106 μg 100 g-1), B2 (2.28 to 4.14 μg 100 g-1), G1 (43.84 to 122.72 μg 100 g-1) and G2 (2.94 to 32.0 μg 100 g-1). A reduction in crude protein (7-10.1%) and crude fat (11.5 to 14.7 %) and an increase in NFE (24.8 to 32.8%) were observed during inoculation. Ash and fiber were not affected while moisture was increased (11.3 to 132.1%) due to addition of spores in solution form. Various minerals like Ca, P, Pb, Mg, Fe, Zn, Se, and K were decreased while Na, Mn, Cu, and Cd increase. Interaction of aflatoxins with proximate and mineral showed that B1 was positively correlated with moisture, crude fat, NFE, Zn, Mg, and Ca while negatively correlated with ash, Fe, Cu, Mn, Cd, Se, Na, and K. Aflatoxin B2 showed positive relation with protein, Cd, Zn, Na, and P. An inverse proportion of this toxin was observed with fiber, Fe, Cu, Pb, K, Mg, and Ca. The response of G1 was positive towards moisture, crude fat, NFE, Zn, Mg, and Ca. A negative effect of Iron, Cu, Mn, Cd, Se, Na, and K was noted on G1. Aflatoxin G2 showed an inclining behavior towards ash, Fe, Mn, Pb, Se, and K. A decline of this toxin was found with Zn and P. It is concluded that growth of A. flavus and aflatoxin production had a significant effect on the chemical composition of the substrate. Any supplementation or reduction of certain constituent genetically or chemically may cause reduction in aflatoxin production, which would be a possible way of risk management of aflatoxins.