83B-22 |
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S. CHI1, S. Zivanovic1, J. Weiss1, and F. A. Draughon2. (1) Dept. of Food Science & Technology, Univ. of Tennessee, Food Chemistry & Biophysics Labs., 2605 River Dr., Knoxville, TN 37996-4591, (2) Food Safety Center of Excellence, Univ. of Tennessee, Dept. of Food Science & Technology, 2605 River Dr., Knoxville, TN 37996-4591 Recant research has shown that biodegradable chitosan films are effective in reduction of microbial growth on fresh and processed foods. Of special interest are chitosan films enriched with oregano essential oil (OEO) because they exhibited strong bactericidal effects toward Escherichia coli O157:H7 and Listeria monocytogenes. The objectives of this research were (1) to evaluate effects of oregano essential oil on mechanical properties of chitosan films, (2) to assess effects of food products on mechanical properties of the films, and (3) to determine stability of active compounds of OEO when incorporated into chitosan matrix. The films were prepared from dispersions containing 1% chitosan in 1% acetic acid solution with addition of 0, 1, and 2% OEO and 0.5% surfactant. Film thickness, water vapor permeability (WVP), puncture force (PF), tensile strength (TS), and elongation were determined before and after application of films on bologna slices. Qualitative and quantitative analyses of OEO were conducted with Shimadzu GCMS-QP5000 on SPB-1 column. Addition of OEO resulted in increased thickness of chitosan films from 0.107 to 0.306 and 0.425 mm with 0, 1, and 2% OEO, respectively. Mechanical properties of the films were significantly altered by addition of OEO and after application on the meat product. TS of pure chitosan films (105.66 N/mm2) decreased to 28.18 and 17.35 N/mm2 in the films with 1 and 2% OEO. Similarly, PF was more than 5 times lower after application of the films on bologna than before the application. As expected, WVP of pure chitosan films (28.5 g/m2hr) was reduced by incorporation of nonpolar compounds of OEO. The major fraction of OEO appeared to be thymol represented with 58.96% of the oil. Our results indicate feasibility of antimicrobial chitosan-essential oil films in food packaging. This data will assist with optimizing functional and mechanical properties of the films.
Session 83B, Food Packaging: Applications of edible coatings, antimicrobial films, and sensors in food packaging
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