title: Antimicrobial Activity of Chitosan Films With Essential Oils AgainstListeria monocytogeneson Cabbage.
abstract: BACKGROUND
  The highest incidence of listeriosis, due to consumption of ready-to-eat foods and fresh, shredded, minimally processed vegetables, occurs among pregnant women and the elderly. In order to reduce the prevalence of listeriosis among consumers, better protective measures are recommended. Chitosan films, with or without added essential oils, represent a modern, safe method of preserving the quality of such vegetables and significantly reducing the incidence ofListeria monocytogenesin these foods.
  
  
  OBJECTIVE
  The present study was conducted to evaluate the antimicrobial properties of composite chitosan-gelatin films with and without essential oils against two strains ofL. monocytogenes, ATCC 19115 and ATCC 19112, in fresh shredded cabbage.
  
  
  METHODS
  Shredded cabbage was inoculated withL. monocytogenesand packed between two layers of the chitosan composite film, then placed in Petri dishes. The prepared samples were stored at 4°C then analyzed for total viable count on PALCAM agar while incubated at 37°C, every 24 hours for 7 days.
  
  
  RESULTS
  AverageL. monocytogenescontent ranged from 4.2 - 5.4 log CFU/g, reaching values of 7.2 - 8.6 log CFU/g in samples of untreated cabbage. A complete reduction ofL. monocytogenesATCC 19115 on cabbage was achieved after 120 hours in the presence of 0.5% chitosan film, whereas reduction ofL. monocytogenesATCC 19112 was achieved after 144 hours. In the presence of 1% chitosan film, the bacteria withered more quickly and complete reduction of both species ofL. monocytogeneswas achieved after 96 hours.
  
  
  CONCLUSIONS
  All tested formulations of chitosan films exhibited strong antimicrobial activity on the growth of both strains ofL. monocytogeneson cabbage. The best effect was achieved with a 1% chitosan concentration. The addition of essential oils increased the antimicrobial activity of all tested films.
authors: Higher Medical and Business - Technological School of Professional Studies, Sabac, Serbia.
authors: Gordana D
authors: GD
authors: Jovanovic
authors: Faculty of Agriculture, Department for Industrial Microbiology, Institute for Food Technology and Biochemistry, University of Belgrade, Belgrade, Serbia.
authors: Anita S
authors: AS
authors: Klaus
authors: Faculty of Agriculture, Department for Industrial Microbiology, Institute for Food Technology and Biochemistry, University of Belgrade, Belgrade, Serbia.
authors: Miomir
authors: M
authors: P Niksic
keywords: Cabbage; Chitosan; Essential Oils; L. monocytogenes