PACKAGING TECHNOLOGY AND SCIENCE
Packag. Technol. Sci. 2006; 19: 259–268
Published online 19 April 2006 in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/pts.729
Characterization of Antimicrobial Films
Containing Basil Extracts
By Panuwat Suppakul,
1
Joseph Miltz
2
* Kees Sonneveld
3
and
Stephen W. Bigger
3
1
Department of Packaging Technology, Faculty of Agro-Industry, Kasetsart University, Bangkok,Thailand
2
Department of Biotechnology and Food Engineering,Technion-Israel Institute of Technology, Haifa, Israel
3
Packaging and Polymer Research Unit, School of Molecular Sciences,Victoria University, Melbourne, Australia
The properties of low-density polyethylene (LDPE)-based films containing either
linalool or methylchavicol as antimicrobial (AM) additives were evaluated. Slight
decreases in transparency, water vapour and oxygen transmission rates were found
in the extruded films containing 0.34% w/w linalool or methylchavicol. The
infrared (IR) spectra of the AM films were similar to that of additive-free LDPE
film. However, carbonyl peaks could also be observed in the spectra of the AM
films. There was no significant difference in the degree of crystallinity and the
melting temperature range of the different films. Derivative thermogravimetry
mass-loss curves showed that the thermal decomposition temperatures of the
AM films were marginally lower than that of LDPE film. Electron micrographs
indicated that AM LDPE-based films exhibited no evidence of changes in
microstructure to suggest that linalool and methylchavicol were not evenly
distributed in the film. Copyright © 2006 John Wiley & Sons, Ltd.
Received 6 September 2005; Revised 11 November 2005; Accepted 6 January 2006
KEY WORDS: antimicrobial packaging; characterization; basil; linalool; methylchavicol
* Correspondence to: J. Miltz, Department of Biotechnology and Food Engineering,
Technion-Israel Institute of Technology, Haifa 32000, Israel.
E-mail: jmiltz@tx.technion.ac.il
Contract/grant sponsor: Australian Agency for International Development
Contract/grant sponsor: Fund for the Promotion of Research,
Technion-Israel Institute of Technology
Copyright © 2006 John Wiley & Sons, Ltd.
INTRODUCTION
The quality and safety of foods may deteriorate
due to surface growth of spoilage or pathogenic
microorganisms. Antimicrobial (AM) additives are
often mixed directly into foods to control microbial
growth and extend shelf-life.
1
However, direct
addition of AM additives into foods has often been
found to have limited benefits.
2
Also, incorporat-
ing AM additives directly into the food involves
relatively large quantities of the additive that, on
the one hand, are not required for preservation
(since microbial spoilage occurs primarily on the
food surface) and, on the other hand, may impart
an off-flavour. Antimicrobial packaging is an alter-
native method to avoid the drawbacks involved in
direct additive incorporation into the product with
the aim of minimizing microbial load. Among
other publications that appeared recently on this
subject are those of Appendini and Hotchkiss
3
and Suppakul et al
4
. Examples of AM materials
evaluated for food packaging applications include
imazalil-impregnated low-density polyethylene
(LDPE),
5
potassium sorbate incorporated in