Development of Flexible Antimicrobial Films Using Essential Oils as Active Agents

• Published in: Journal of agricultural and food chemistry Vol. 55; no. 21; pp. 8814 - 8824
• Main Authors: López, P., Sánchez, C., Batlle, R., Nerín, C.
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 17-10-2007
• Subjects: Anti-Infective Agents - administration & dosage; antibacterial properties; antifungal properties; Antimicrobial packaging; Aroma and flavouring agent industries; Aspergillus flavus; Bacillus cereus; Biological and medical sciences; Candida albicans; cinnamaldehyde; Cinnamomum zeylanicum; Cinnamomum zeylanicum - chemistry; cinnamon; Clove Oil - chemistry; cloves; Debaryomyces hansenii; Enterococcus faecalis; Escherichia coli; essential oil; essential oils; ethylene vinyl alcohol copolymer; Eugenia; Eurotium; Food industries; Food microbiology; food packaging; Food Packaging - instrumentation; food pathogens; food preservatives; Fundamental and applied biological sciences. Psychology; Gram-negative bacteria; Gram-positive bacteria; Listeria monocytogenes; migration; Oils, Volatile - administration & dosage; oregano; Origanum - chemistry; Origanum vulgare; packaging materials; Penicillium islandicum; Penicillium nalgiovense; Penicillium roqueforti; Plant Oils - administration & dosage; plastic film; Plastics; polyethylene; polyethylene/ethylene vinyl alcohol copolymer; polypropylene; polypropylenes; Pseudomonas aeruginosa; Safety/Toxicology; Salmonella choleraesuis; single-drop microextraction; Staphylococcus aureus; Syzygium aromaticum; Yersinia enterocolitica; polyethylene/ethylene vinyl alcohol copolymer; Antimicrobial packaging; single-drop microextraction; migration; polypropylene; essential oil; Polyethylene; Film; Migration; Alcohol; Antimicrobial agent; Development; Packaging; Ethylene copolymer; Essential oil; Conditioning
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf071737b

The antimicrobial activity in the vapor-phase of laboratory-made flexible films of polypropylene (PP) and polyethylene/ethylene vinyl alcohol copolymer (PE/EVOH) incorporating essential oil of cinnamon (Cinnamomum zeylanicum), oregano (Origanum vulgare), clove (Syzygium aromaticum), or cinnamon fortified with cinnamaldehyde was evaluated against a wide range of microorganisms: the Gram-negative bacteria Escherichia coli, Yersinia enterocolitica, Pseudomonas aeruginosa, and Salmonella choleraesuis; the Gram-positive bacteria Listeria monocytogenes, Staphylococcus aureus, Bacillus cereus, and Enterococcus faecalis; the molds Penicillium islandicum, Penicillium roqueforti, Penicillium nalgiovense, Eurotium repens, and A spergillus flavus and the yeasts Candida albicans, Debaryomyces hansenii, and Zigosaccharomyces rouxii. Films with a nominal concentration of 4% (w/w) of fortified cinnamon or oregano essential oil completely inhibited the growth of the fungi; higher concentrations were required to inhibit the Gram-positive bacteria (8 and 10%, respectively), and higher concentrations still were necessary to inhibit the Gram-negative bacteria. PP films were more effective than PE/EVOH films. The atmospheres generated by the antimicrobial films inside Petri dishes were quantitatively analyzed using headspace-single drop microextraction (HS-SDME) in combination with gas chromatography–mass spectrometry (GC–MS). The analyses showed that the oregano-fortified PP films released higher levels of carvacrol and thymol, and the cinnamon-fortified PP films released higher levels of cinnamaldehyde, during the first 3–6 h of incubation, than the corresponding PE/EVOH films. Shelf-life tests were also performed, demonstrating that the antifungal activities of the films persisted for more than two months after their manufacture. In addition, migration tests (overall and specific) were performed, using both aqueous and fatty simulants, to ensure that the films meet EU regulations regarding food contact materials. Following contact with the tested films, the substances that had migrated into the aqueous simulants were recovered by direct immersion-single drop extraction (DI-SDME) and then analyzed by GC–MS. The fatty stimulant (isooctane) was directly injected into the chromatographic system.