Antimicrobial and physical properties of edible chitosan films enhanced by lactoperoxidase system

Abstract: Effects of lactoperoxidase system (LPOS) incorporated directly into chitosan films at different concentrations (0.5, 1 and 1.5%) were studied. Films obtained were tested on the inhibition of phytopathogenic strains such as Xanthomonas campestris pv. Mangifera indica, Colletotrichum gloeosporioides (C. 64, C. 4612 and C. 62) and Lasiodiplodia theobromae ngr 05A. Water vapor permeability and mechanical properties of films with LPOS and/or not iodine were also studied. Antibacterial effect obtained by disc diameter technique indicated that chitosan concentration at 1 and 1.5% (w/w) incorporated with LPOS and/or not iodine inhibited higher X. campestris pv. M. indica than chitosan film alone or at low concentrated of 0.5% incorporated by LPOS. The antimicrobial technique using puncture gave very good information on the antifungal effect and on the variability in susceptibility of strains of fungi. C. gloeosporioides C64 and L. theobromae were inhibited completely by 1 and 1.5% chitosan incorporated by LPOS contained or not iodine, while C. gloeosporioides C4612 was sensitive to the presence of iodine and C62 were resistant strains. The properties of chitosan films were not significantly changed by the incorporation of the enzyme system. [Copyright &y& Elsevier]