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Talks and Poster Presentations (with Proceedings-Entry):

C. Fleischberger, V. Archodoulaki, I. Steiner:
"Influence Of Active Packaging Materials On Microorganisms Of Selected Food Stuffs";
Poster: Eurofoodchem Xvii, Istanbul; 05-07-2013 - 05-10-2013; in: "Eurofoodchem Xvii - Book of Abstracts", H. Köksel (ed.); (2013), ISBN: 978-605-63935-0-1; 695.



English abstract:
The aim of this study was to produce thermoplastic films including "traditional" harmless food preservatives such as sorbic acid, citric acid, or their respective salts by simple methods such as extrusion. The focus here is on the evaluation of the antimicrobial efficiency of the films rather than on the production of the materials or material properties.
The films were produced with an ethylene-octene copolymer as a basis in order to achieve a low handling temperature and to avoid the loss of active substances through decomposition. It was therefore possible to incorporate sorbic acid, potassium sorbate, citric acid, and mono-sodium citrate in the polymer matrix.
In a first step the migration of the active substances out of the material was tested using water or 10 % ethanol as a food simulant. It could be shown that most of the citric acid and citrate, but only a limited amount of the sorbic acid and sorbate migrated.
Secondly the effect of the films on the growth of some specific bacteria, Carnobacterium divergens and Escherichia coli K-12, was tested by contaminating the surface of the films with a bacterial suspension and overlaying with a nutritional medium. It turned out that all of the substances in fact inhibited the growth of the bacteria, but the amounts needed in the polymer to achieve the effect varied a lot (5 % - 50 % of the weight).
Finally the films that proved effective against E. coli and C. divergens were used to wrap raw meat (beef and turkey). The meat was stored at 5°C for one week and total plate count of the samples was determined before and after the storage in the active films or in reference LDPE films. Samples in citric acid and citrate films showed 3-4 log cfu less bacteria as compared with the reference samples. The samples in sorbic acid and sorbate films on the other hand showed no significant differences to the references. This difference may be explained by the different migration behavior noted before.
Conclusively it can be said that polymeric films containing citric acid or mono-sodium citrate might be a cheap and effective way for active antimicrobial packaging, but more research will certainly be necessary.

German abstract:
Das Ziel der Arbeit bestand darin, thermoplastische Filme mit einfachen Methoden wie der Extrusion zu produzieren, die traditionell als harmlos geltende Substanzen wie Citronensäure, Sorbinsäure bzw. deren Salze an das verpackte Lebensmittel abgeben, um die Vermehrung von Mikroorganismen zu verhindern oder zu verlangsamen.


Electronic version of the publication:
http://publik.tuwien.ac.at/files/PubDat_218870.pdf


Created from the Publication Database of the Vienna University of Technology.