Inhibitory Effect of Acetic Acid on Aspergillus flavus Growth and Kojic Acid and Aflatoxin B1 Production in Stored Corn

Abstract

The aim of this work was to study the effect of acetic acid on growing of local isolate of Aspergillus flavus which contaminated stored corn and on produced the kojic acid and aflatoxin B1 , The acid were added with 0.5 , 1 , 3 , and 5 % compared with other control treatment of no added acids to stored corn . Samples were stored in closed room and the temperature was measured each month. Moisture percrnt , pH value, total count of fungus and concentration of kojic acid and Aflatoxin B1 in all treatments at the beginning and at the end of the month were measured . Results indicated that moisture content did not significantly change through different treatments with different concentration added of acid and at three different period of storage, The moisture percent in corn was ranged between 17.0 to 18.25 % . pH values were decreased in corn with added of acid, The value was decreased from 6.7 at the beginning of the storage to lowest level ( 3.64 ). Growth of A.flavus was inhibited and its count was decreased in corn of treatment with the above acid comparing with control treatment , The total count was ranged between 0.75 – 0.95 × 104 CFU / g when acid added with 0.5 % and this less than the number which found in control treatment , The growth of fungus decreased by 100% in case of addition of 1 , 3 and 5 % of acetic acid . Production of kojic acid and aflatoxin B1 by A.flavus in stored corn inhibited with addition of acetic acid , The concentration of the two substances ranged between 11.6 – 13.3 g / Kg and 29.5 – 47.5 µg / kg , respectively after using the acid with 0.5% , and this less than the levels in control treatment. Addition of acetic acid with 1% or above inhibited the production kojic acid and aflatoxin B1 by A.flavus complete .