Synergistic properties of mustard and cinnamon essential oils for the inactivation of foodborne moulds in vitro and on Spanish bread

This work was performed to evaluate the antifungal effect of cinnamon and mustard essential oil (EO) alone and in combination against a range of mould strains. A wide range of resistance levels was observed among different mould species, being R. stolonifer the most resistant one. Mustard EO showed the biggest antifungal effect, and for this reason it was selected to study its effect in vapour phase on bread. The shelf life of bread inoculated with R. stolonifer and non- inoculated increased by 3-4 days at 25 degrees C, while at 4 degrees C the shelf-life increased beyond 50 days. However, the results from the acceptability test were negative. Based on this, the antifungal effect of cinnamon/mustard EO in combination was evaluated, with results mostly additive and synergistic. The ratio of the combination was defined taking into account the most resistant strain (100:8, cinnamon and mustard respectively) and their application was performed in vapour phase. This combination maintained the antifungal activity presented by mustard EO by itself and masked the mustard flavour, providing positive results in the acceptability tests. It was therefore suggested to be used at industrial scale.