Potential of the polymer poly-[2-(tert-butylamino) methylstyrene] as antimicrobial packaging material for meat products

AIMS

The objective of the study was to investigate the antimicrobial potential of a new SAM(®) polymer poly(TBAMS) as packaging material for meat products.

METHODS AND RESULTS

The influence of temperature, time and product factors on the antimicrobial activity of poly(TBAMS) against different bacteria was determined using a modified test method based on the Japanese Industrial Standard 2801:2000. Results showed a significant reduction in bacterial counts on poly(TBAMS) compared with the reference material of several meat-specific micro-organisms after 24 h at 7°C. Bacterial counts of Staphylococcus aureus, Listeria monocytogenes, Lactobacillus spp., Brochothrix thermosphacta and Escherichia coli were reduced by >4·0 log10  units. Pseudomonas fluorescens was less sensitive to poly(TBAMS) within 24 h between 2 and 7°C. Prolonging the storage time to 48 h, however, resulted in an increased reduction rate. Furthermore, antimicrobial activity was also observed if meat components in the form of meat extract, meat juice or bovine serum albumin protein were present. Antimicrobial activity was also achieved if inoculated with mixed cultures.

CONCLUSIONS

Poly(TBAMS) showed antimicrobial properties under conditions typical for meat supply chains.

SIGNIFICANCE AND IMPACT OF THE STUDY

Poly(TBAMS) bears a high potential to increase safety and shelf life of meat products.

Molecular Structure of the Hard Segments in Flexible Foams

The main basis of structure-property-relationships of polymeric materials is a good characterization of the structure under study. Such is the case for cross linked polyurethanes such as flexible foams. To overcome the problems of solubility of these materials, a selective degradation process was used, leaving the hard segments unaffected. These were then analyzed by MALDI-TOF (Matrix Assisted Laser Desorption-Ionization Time of Flight mass spectrometry).

Using these techniques, the length distribution of the hard segments was examined. It was found that the length of the hard segments decreases much slower for polyester foams than for polyether foams. This fact was attributed to a lower solubility of the hard segments in polyethers, which leads to an earlier onset of phase separation. Thus, both mobility and reactivity of the segments in the segregated hard domains are reduced. This fact also explains why the length of the hard segments is only slightly dependent on the water content, or the index, at least in polyether foams.

Chemical differences such as the incorporation of polymeric MDI or reactive catalysts could also be shown. Furthermore, this work shows for the first time that presence of cyclic hard segments could be established in a foam.