EFFECT OF MEXICAN OREGANO (LIPPIA BERLANDIERI SCHAUER) ESSENTIAL OIL FRACTIONS ON THE GROWTH OF ASPERGILLUS SPP. IN A BREAD MODEL SYSTEM

Spices acting as antimicrobial agents can be used in combination with other factors to assure food safety. The aim of this work was to evaluate the effect of Mexican oregano (Lippia berlandieri Schauer) essential oil (EO) fractions on the growth of Aspergillus spp. using a bread model media. Fungal growth was evaluated on a wheat flour-based medium with controlled A(w) (0.925, 0.950) and with five Mexican oregano EO fractions with different concentrations of thymol and carvacrol (50-200 mg/kg). Fungal growth (modified Gompertz equation) was affected by A(w) values and the concentration of Mexican oregano EO fractions. Differences on thymol and carvacrol had no significant effect on the fungal growth kinetic parameters. Low A(w) (0.925) and fractions with high concentration of carvacrol (1 and 2) at 100 mg/kg showed fungicidal activity. Combined methods for food preservation can include Mexican oregano EO, where Aspergillus spp. fungal growth can be inhibited.