Properties of antimicrobial plastics containing traditional food preservatives

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 70-120 mm), 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 2.5-15% 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/dm 2 , no antimicrobial activity was observed.

Antimicrobial compression-moulded wheat gluten films containing potassium sorbate

“…This suggests a specific susceptibility of F. incarnatum towards PS. Vartiainen, Skytta, Enqvist, and Ahvenainen (2003) added potassium sorbate to synthetic plastics to produce antimicrobial packaging materials. They found that films containing 15 wt.% PS showed antimicrobial activity towards Bacillus subtilis, but not against A. niger or Escherichia coli.…”

Development of mono and multilayer antimicrobial food packaging materials for controlled release of potassium sorbate

“…Previously, different research groups added Psb in whey protein; k-carregeenan; cellulose triacetate; poly (maleic acid-co-olefine); polystyrene; polyethylene terephthalate; low density polyethylene and copolymer of vinylidene chloride (Choi et al, 2005;Han & Floros, 1997;Fama, Flores, Gerschenson, & Goyanes, 2006;Ozdemir & Floros, 2003;Limjaroen, Ryser, Lockhart, & Harte, 2003;Flores et al, 2007;Vartiainen, Skytta, Enqvist, & Ahvenainen, 2003;Ye, Neetoo, & Chen, 2008). These published results indicate quick desorption of the Psb from the film, inducing a rapid loss of its activity.…”

Use of antimicrobial methylcellulose films to control Staphylococcus aureus during storage of Kasar cheese

“…3,6,7 However, the health concerns of consumers, environmental problems and increased demand for additive-free foods limit the use of chemical antimicrobial agents in food packaging. 3,8 physiologically active polyphenols.…”