After the individual tests on strawberries were performed, essential oil combinations were evaluated on inoculated strawberries, using a checkerboard design that included the MIC of one essential oil, 1⁄2 MIC, 1⁄4 MIC, and 1⁄8 MIC in combination with the same proportions of the other essential oil, using the previously described methodology, taping two 25 mm2 pieces of Whatman® No. 1 filter paper to the upper side of the container, one for each essential oil. Inoculation and incubation were performed as previously described. Observations of mold growth were made daily during 5 days. The percentage of inoculated wounds that presented mold growth was calculated. Every experiment was per- formed by triplicate.
Once essential oils MICs were obtained for tested combinations, the fractional inhibitory concentrations (FICs) were calculated according to López-Malo et al. (2005b):