Antimicrobial effects of corn zein films impregnated with nisin, lauric acid, and EDTA.
Bacterial growth during food transport and storage is a problem that may be addressed with packaging materials that release antimicrobials during food contact. In a series of five experiments, EDTA, lauric acid (LA), nisin, and combinations of the three antimicrobial agents were incorporated into a corn zein film and exposed to broth cultures of Listeria monocytogenes and Salmonella Enteritidis for 48 h (sampled at 2, 4, 8, 12, 24, and 48 h). Four experiments used starting cultures of 10(8) CFU/ml in separate experiments tested against each bacterium; the fifth experiment examined the inhibitory effect of selected antimicrobial agents on Salmonella Enteritidis with an initial inoculum of 10(4) CFU/ml. L. monocytogenes cell numbers decreased by greater than 4 logs after 48 h of exposure to films containing LA and nisin alone. No cells were detected for L. monocytogenes (8-log reduction) after 24-h exposure to any film combination that included LA. Of all film agent combinations tested, none had greater than a 1-log reduction of Salmonella Enteritidis when a 10(8)-CFU/ml broth culture was used. When a 10(4) CFU/ml of Salmonella Enteritidis initial inoculum was used, the films with EDTA and LA and EDTA, LA, and nisin were bacteriostatic. However, there was a 5-log increase in cells exposed to control within 24 h. The results demonstrate bacteriocidal and bacteriostatic activity of films containing antimicrobial agents.
Hoffman
K L
KL
Department of Food Science and Human Nutrition, Clemson University, South Carolina 29634-0371, USA.
Han
I Y
IY
Dawson
P L
PL
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D018441:Biofilms; D015169:Colony Count, Microbial; D004338:Drug Combinations; D004357:Drug Synergism; D004492:Edetic Acid / Q000494:pharmacology; D005503:Food Additives; D007850:Lauric Acids / Q000494:pharmacology; D008089:Listeria monocytogenes / Q000187:drug effects* / Q000254:growth & development; D009561:Nisin / Q000494:pharmacology; D012477:Salmonella enteritidis / Q000187:drug effects* / Q000254:growth & development; D013997:Time Factors
D000900:Anti-Bacterial Agents; D004338:Drug Combinations; D005503:Food Additives; D007850:Lauric Acids; C030358:lauric acid; D009561:Nisin; D004492:Edetic Acid