Properties of antimicrobial plastics containing traditional food preservatives
Authors: Vartiainen J.1; Skytta E.1; Enqvist J.2; Ahvenainen R.1
Source: Packaging Technology and Science, Volume 16, Number 6, November 2003 , pp. 223-229(7)
Publisher: John Wiley & Sons, Ltd.
Abstract:
Traditional food preservatives, sodium benzoate, sodium nitrite, potassium sorbate and sodium lactate, were incorporated into synthetic plastics, low-density polyethylene (LDPE), poly(maleic acid-co-olefine), polystyrene (PS) and polyethylene terephthalate (PET), aimed at producing antimicrobial packaging material for foodstuffs. The study was undertaken on plaques (thickness 2 mm) and films (thickness 70120 µm), whose antimicrobial test results clearly differed. Plaques containing 15% sodium nitrite inhibited both Aspergillus niger and Bacillus subtilis, whereas the same concentration of sodium benzoate and potassium sorbate had activity only against B. subtilis. Sodium lactate-containing samples did not have any antimicrobial activity and none of the samples inhibited Escherichia coli. Antimicrobial substances added into PS and PET produced the strongest activities; however, due to the brittle structure of these materials, they were not tested further. Thus, more thorough tests for antimicrobial activity, migration and oxygen and water vapour permeability were carried out using LDPE films with 2.515% sodium benzoate and sodium nitrite. The effects of both substances on permeability properties were negligible. Although the total migration into food simulants measured from the films in many cases exceeded the limit value of 10 mg/dm2, no antimicrobial activity was observed. Copyright © 2003 John Wiley & Sons, Ltd.Keywords: plastics; antimicrobial properties; food packaging
Document Type: Research article
DOI: 10.1002/pts.629
Affiliations: 1: VTT Biotechnology, Tietotie 2, Espoo, P.O.Box 1500, FIN-02044 VTT, Finland 2: VTT Processes, Sinitaival 6, P.O.Box 1607, FIN-33101 Tampere, Finland

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