Combinações de ácidos orgânicos no controle de Aspergillus spp. micotoxigênico

Abstract

Consumers are more aware of the importance of consuming healthy and quality food products. The presence of mycotoxins in the diet is a major risk to human and animal health and cause severe economic losses. The mycotoxigenic molds of the genus Aspergillus are responsible for the production of aflatoxin and ochratoxin during storage of grains and cereals. There are toxins resistant to physical and chemical treatments and thus, measures to reduce or prevent the product of these toxins are necessary. The elimination of mold or the impediment of its development are preventive measures to avoid the contamination by these mycotoxins.The objective of this work was to evaluate the combinations of organic acids against A. flavus and A. ochraceus regarding the antifungal activity and the effect of these for the control of aflatoxin production by A. flavus. The Inhibitory Minimal Concentration (MIC) of propionic, acetic and lactic acids was determined through in vitro analyzes against A. flavus NRRL 3251 and A. ochraceus A152 strains. From the CIM, the tests were designed to evaluate the combinations of organic acids against A. flavus. The best combination was tested and applied in pelleted ration to control toxigenic A. flavus. The MIC of propionic acid of 0.2% and acetic acid of 0.5% were the organic acids with the highest activity against A. flavus and A.ochraceus. In the combinations against A. flavus the MIC of 0.025 ± 0.25 % (propionic and acetic acid) was the most efficient demonstrating the importance of synergism and the possibility of applying lower doses of the acids. It was not possible to evaluate the effect of organic acids on the production of aflatoxin by strain NRRL 3251, although this one is toxigenic, it did not express the production of the toxin throughout the experiment, probably due to storage problems of the fungal culture. It was not possible to evaluate the effect of the combined acids on artificially pelleted ration contaminated with A. flavus due to the low feed water activity (~ Aw 0,6), which represented the main barrier to fungal growth, and further studies And applied to food under storage conditions in which the effect can be observed. Organic acids have inhibitory activity against Aspergillus spp. And through this work it was possible to observe that the combination of two acids allows the reduction of the applied dose. However, when transposing the in vitro analysis for the experiments, it is recommended to study the intrinsic and extrinsic factors in which this experiment is conducted, in order to be able to evaluate the best treatments.