Chitosan‐coated paper: Effects of nisin and different acids on the antimicrobial activity

Abstract Chitosan coatings prominently improved both the gloss and oxygen barrier properties of paper. The gloss value in the machine direction was increased as a function of added chitosan. An oxygen‐permeability value of 1.1 cm 3 /m 2 d was obtained when 6.9 g/m 2 chitosan was applied to 80 g/m 2 copy paper. In addition, the effects on the mechanical properties were positive, but not significant. The water‐vapor permeability of the paper increased as a result of the chitosan coating. Chitosan dissolved in 1.6, 3.2, and 6.4% lactic acid showed antimicrobial activity against Bacillus subtilis , whereas acetic and propionic acids (1.6, 3.2, and 6.4%) did not produce any notable activity. Nisin (0.08 g/L) did not enhance the antimicrobial activity of coatings prepared from chitosan dissolved in different acids. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 986–993, 2004