Fractionation of aflatoxins showed the absence of aflatoxin in the filtrates of all isolated fungi, except the filtrate of yellow corn grains infected with Aspergillus flaws. The production of aflatoxins by A. flavus was affected by grade of grains (grade 1,3 and 5) as well as its moisture content (17 and 23% moisture) so the, production was increased from grade one to grade five and from 17% to 23% moisture content within each grade. Also, the concentration of aflatoxin B1 is higher than aflatoxin B2. The production of aflatoxins were increased by increasing storage temp., grains moisture content and storage period. Grade three showed the highest amounts of both Bl (986 p g/kg) and B2 (219 p g/kg) followed by grade five (237 pg/kg of B1 and B2, respectively). While the least amount of both B1 and B2 were shown in grade one (32.9 and S.48 pg/kg). Protein content was decreased with moisture percentage either low (17%) or high (23%) when stored under low temperature (10°C or 18°C) for storage period long as 90 days compared with the control. While the stored under high temperature (28°C or the room temperature, 25-30°C) for a storage of 30 days decreased the protein content with 17% moisture mid increased to the max (100%) with 23% moisture. Reduction in concentration of amino acid proline (in all tested grates) caused when storage the grains with either low moisture (17%) or high moisture (23%) under high temp. (286C or 25 - 30°C). Total carbohydrates content of grains was slightly increased when stored either higher or low temp. Grading of grains had an effect on total carbohydrates, where grade one showed the least increase followed by grade three and grade five recorded the highest one, especially with 17% at 10°C or 23% and 28°C. |
