Journal
JOURNAL OF FOOD PROTECTION
Volume 77, Issue 7, Pages 1153-1160Publisher
INT ASSOC FOOD PROTECTION
DOI: 10.4315/0362-028X.JFP-13-545
Keywords
-
Funding
- U.S. Department of Agriculture National Institute of Food and Agriculture competitive grants program
- University of Massachusetts through the Commercial Ventures and Intellectual Property Technology Development Fund
- Peter Salmon Graduate Fellowship (Department of Food Science, University of Massachusetts Amherst)
- Northeast Alliance Fellowship
Ask authors/readers for more resources
Several studies have demonstrated that metal chelators enhance the antimicrobial activity of lysozyme. This study examined the effect of metal-chelating active packaging film on the antimicrobial activity of lysozyme against Listeria monocytogenes. Polypropylene films were surface modified by photoinitiated graft polymerization of acrylic acid (PP-g-PAA) from the food contact surface of the films to impart chelating activity based on electrostatic interactions. PP-g-PAA exhibited a carboxylic acid density of 113 +/- 5.4 nmol cm(-2) and an iron chelating activity of 53.7 +/- 9.8 nmol cm(-2). The antimicrobial interaction of lysozyme and PP-g-PAA depended on growth media composition. PP-g-PAA hindered lysozyme activity at low ionic strength (2.48-log increase at 64.4 mM total ionic strength) and enhanced lysozyme activity at moderate ionic strength (5.22-log reduction at 120 mM total ionic strength). These data support the hypothesis that at neutral pH, synergy between carboxylate metal-chelating films (pK(a)(bulk) 6.45) and lysozyme (pI 11.35) is optimal in solutions of moderate to high ionic strength to minimize undesirable charge interactions, such as lysozyme absorption onto film. These findings suggest that active packaging, which chelates metal ions based on ligand-specific interactions, in contrast to electrostatic interactions, may improve antimicrobial synergy. This work demonstrates the potential application of metal-chelating active packaging films to enhance the antimicrobial activity of membrane-disrupting antimicrobials, such as lysozyme.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available