Aflatoxin; How to Avoid Aflatoxins in Food?

The life cycle of Aspergillus species

Aspergillus flavus and Aspergillus niger mainly produce aflatoxins. Both of these species have almost the same life cycle. Therefore, the spores produced from the life cycle of these fungi are aflatoxins. Unlike other pathological organisms, these fungi grow in the winter season in the soil. Therefore, it looks like propagules or decaying matter. This is the mycelium of the fungi, which is the main body for the growth and reproduction of the fungi. The thick hard mass of this fungi is specifically called sclerotia.

Although every fungus has its way of conjugation, that is, sexual reproduction, the fungi of this class reproduce asexually through conidia. The growth and extension of the hyphae make conidia. The hyphae which produce conidia are called conidiophores. The conidia are spread through the whirl of wind and insects, just like the phenomenon of pollination. Wherever these conidia land, they infect them. This means that the settling of these spores finally creates a new area of fungal germination. A new Aspergillus mycelium is produced this way, and the aflatoxins are spread through asexual reproduction of Aspergillus species.

The conidia land on the grains and legumes and infect them. The infection is mostly observed in the corn kernels, which happens because of the settling of the conidia in the corn silk. A similar process is repeated. The conidia, after settling down, form a mycelium from which hyphae grow into conidiophores and finally produce conidia. Sometimes, conidia fall onto the surface of leaves, where the insects feed on them and destroy the leaves as well. This is known as secondary inoculation. These conidia may settle on the soil and through rainwater in other cases. This is how oily plants such as peanuts and sunflowers get infected.