Document Type : Research Article
Different species of Aspergillus growth on food and feed and by producing of secondary metabolites including aflatoxin, cause a lot of damage and reduce the value of their food. In this study the effect of different concentrations of citric acid, propionic acid and aloe vera extract on colony growth of the Aspergillus flavus and Aspergillus parasiticus were evaluated, for this purpose, the desired concentration of the compounds prepared and was added to to Czapek media. Then this environment was inoculated by five-millimeter discs containing fresh culture Aspergillus parasiticus, and the results showed that propionic acid at concentrations of 0.5, 0.8, 1 and 1.5 % completely prevented the growth of the colonies. Citric acid at concentrations of 0.5, 0.8, and 1 % has moderate anti-fungal properties, and the concentration of 1.5 % had no effect on reducing the diameter of the colony. Aloe vera plant extract with a concentration of 2, 4 and 6 % showed a deterrent effect. The relationship between aflatoxin production and sclerotia formation, isolates of Aspergillus flavus and Aspergillus parasiticus were cultured in medium Chapk, And high-pressure liquid chromatography was used to measure aflatoxin level. Compared with the total amount of aflatoxin produced by the isolates, a small sclerotium group produced more aflatoxin than the group without sclerotium and large sclerotium.