Improvement of Antifungal Activity Against Foodborne Molds <i>in Vitro</i> and on Bread by Combination of Cinnamaldehyde with Citral

In order to improve the antifungal activity of natural fungicides to control the fungal contamination on bread products, the synergistic combination of cinnamaldehyde with citral (SCC) against main bread spoilage fungi (Aspergillus niger and Penicillium citrinum) was screened by inhibition zone and checkerboard method tests. The MICs of cinnamaldehyde and citral against both fungi were significantly reduced when presented in SCC. In the in vitro tests, SCC completely inhibited the spore germination and mycelial growth of both fungi at its MIC concentration. Mechanistic investigation revealed that the membrane structures of both fungi were damaged by SCC treatment, which led to massive leakage of cellular components. Meanwhile, SCC-treated resulted in membrane lipid peroxidation and induced intracellular oxidative stress. In the in situ test, the shelf life of bread was prolonged for nine days in the SCC-treated group. These results indicated that SCC is potential as a natural preservative in baked products.