Carvacrol and thymol as potential preservatives against aspergillus in maize grains

Abstract

This study investigated the antifungal potential of carvacrol and thymol against strains of Aspergillus flavus, A. fumigatus, and A. niger. Minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) were determined. The constituents' effect was also evaluated for possible preservative activity against fungal mycelial growth in a maize grain contamination model. At the concentrations tested, carvacrol inhibited the growth of all strains used; thymol did not inhibit the growth of the A. flavus strain tested. For both phytochemicals, the MFCs determined for the A. niger strain were equivalent to the value of their MICs. However for A. flavus and A. fumigatus, the MFC determined for carvacrol was four times its MIC value. At the concentrations tested, these phytochemicals were able to slow fungal mycelial growth, though carvacrol proved to be more effective than thymol in the maize grain contamination model.