The effectiveness of hexamethylenetetramine‐incorporated plastic for the active packaging of foods

Abstract

The feasibility of LDPE films containing 0.2 or 0.5% (w/w) hexamethylenetetramine (HMT) as antimicrobial packaging material to inhibit microbial growth on the surface of foods was investigated. As HMT is allowed in Europe to be used as a preservative under certain conditions, and as it is mentioned on the list of additives notified to the European Commission as substances which may be used in plastics intended in contact with food products, this compound offers good opportunities for the manufacturing of an antimicrobial packaging material. In a first experiment, fresh orange juice was vacuum packaged in LDPE films containing 0, 0.2 and 0.5% (w/w) HMT and stored at 6°C for 39 days. Every day and later every 3 days, packages of orange juice were analysed for yeasts and lactic acid bacteria. The shelf-life of orange juice, could not be prolonged significantly by packaging into a 0.2% or 0.5% (w/w) HMT-containing film. In a second experiment, however, packaging of cooked ham in a 0.5% (w/w) containing LDPE film, significantly affected shelf-life. After 20 days a significant reduction of total aerobic count and lactic acid bacteria was observed. In an additional migration test, it became clear that the level of HMT released into orange juice was close to the specific migration limit of 15 mg CH2O/kg imposed by the EC. Copyright © 2000 John Wiley & Sons, Ltd.