100B-23 |
Antimicrobial activity of chitosan incorporated polyethylene films |
S. I. PARK1, K. S. Marsh2, P. L. Dawson1, J. C. Acton1, and I. Han1. (1) Department of Food Science and Human Nutrition, Clemson University, 224 P&A Bldg., Clemson, SC 29634, (2) Kenneth S. Marsh & Assoc, Ltd., 102B Ole Towne Square, Central, SC 29630 It is well known that chitosan has an antimicrobial activity against various microorganisms. Even though chitosan is still not approved as a food additive, its advantageous properties still generate attentions for food applications. The usage of chitosan as an antimicrobial additive in food packaging films could be one of these advantageous properties The objective of this study was to investigate the feasibility of developing a chitosan based antimicrobial packaging film through the incorporation of chitosan into low density polyethylene (LDPE) film. LDPE powder was coated with chitosan dissolved in lactic acid solution with different ratios and antimicrobial films were formed by heat pressing method. The antimicrobial effectiveness of these films was examined against three pathogenic bacteria. Also, the physical (tensile strength and elongation at break) and barrier (water vapor permeability and oxygen permeability) properties of these films were evaluated. The results showed chitosan could be released from the film matrix and inhibit microbial growth. The antimicrobial activity increased with increasing concentration of chitosan in the film matrix. Both gram positive and gram negative bacteria were inhibited by those antimicrobial films when the incorporation of chitosan was above 1.43%. The antimicrobial effectiveness of films tested was decreased with increasing storage time. The oxygen permeability was not affected by the incorporation of chitosan, while the water vapor permeability was dramatically changed with the addition of chitosan with high concentration (2.14%). The tensile strength was slightly decreased with increasing the chitosan concentration in films. The elongation values were more critically reduced by the addition of chitosan than that of tensile strength. These experiments indicated that chitosan has some attractive properties as food additives and as food packaging materials. The controlled release of chitosan from film matrix seems to effectively inhibit bacterial growth if the amount of chitosan in film matrix is sufficient to inhibit the recovery of microbial growth.
Session 100B, Food Packaging
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