The method for preparation of citric acid through surface cultivation of Aspergillus niger on molasses is applicable in the food processing industry. It increases molasses' capacity to ferment, as well as the product yield without using additional ballast compounds. According to the method, the molasses solutions are treated after preparation through the classic method with citric acid in a quantity of 0.4 to 1.0 g/l, after which the solution is submitted for fermentation.
