EFFECTIVENESS OF CHITOSAN AND SOME ESSENTIAL OILS AS MAIZE GRAIN EDIBLE COATING FILMS ON THE GROWTH OF Escherichia coli AND Staphyllococcus aureus AND SOME MYCOTOXINS PRODUCED BY Fusarium verticilloides AND Aspergillus flavus.

Abstract

Composite film designed as new innovative transparent edible film coating grains was prepared by casting film-forming colloidal emulsions covering maize grains which was based on chitosan and / or cinnamon, basil and dill oils or extracts added to chitosan HMW (high molecular weight). Chitosan individual coating film succeeded as antibacterial and detoxifying agent, the reduction rate of E.coli growth was the highest followed by Fumonisin B1 then aflatoxin B1production at the same(Minimum Inhibitory concentration( MIC). In case of Staphyllococcus aureus: Cinnamon extract at its both tested concentrations showed the best results (79.9 and 75.46 successively in inhibiting Staphyllococcus aureus growth) followed by chitosan at concentration 0.5% which realized (74.29%) growth inhibition. All tested EOs individual coating films succeeded at their MICs as antibacterial and detoxifying agents. The composite coating films are more effective as antibacterial than detoxifying agents except the film composited of chitosan and cinnamon oil which was highly succeeded as antibacterial and detoxifying agent in case of E.coli ,AflatoxinB1 and fumonisinB1the inhibition ratios were 94.145%, 91.217% and 90.01% respectively .Also, the composite film of chitosan and cinnamon extract inhibited E.coli, AflatoxinB1 and fumonisin B1 being: 97.943%,87.259% and 88.370% respectively. Synergistic Effects are more dominant in Bacterial growth inhibition than mycotoxins inhibition whereas, The antagonistic effect was often appeared in case of mycotoxins inhibition except the compound of chitosan and cinnamon oil, which gave the best results in the inhibition of mycotoxins.The composite film of chitosan and basil oil exhibited the highier inhibition ratio onE.coli growth being 98.418% . It is clear from the obtained results that the usage of composite film of chitosan and cinnamon oil can be used effectively to cover and preserve maize grains during storage.