Antimicrobial activity of cyclodextrin entrapped allyl isothiocyanate in a model system and packaged fresh-cut onions

• Published in: Food microbiology Vol. 30; no. 1; pp. 213 - 218
• Main Authors: Piercey, M.J., Mazzanti, G., Budge, S.M., Delaquis, P.J., Paulson, A.T., Truelstrup Hansen, L.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.05.2012; Elsevier
• Subjects: Allyl isothiocyanate; Antifungal; Biological and medical sciences; Colony Count, Microbial; Consumer Product Safety; Cyclodextrin; Cyclodextrins - pharmacology; Encapsulation; Escherichia coli; Escherichia coli O157 - drug effects; Food Handling - methods; Food industries; Food Microbiology; Food Packaging - methods; Food Preservation - methods; Food Preservatives - pharmacology; Food safety; Fresh-cut produce; Fundamental and applied biological sciences. Psychology; General aspects; Hygiene and safety; Isothiocyanates - pharmacology; Listeria monocytogenes; Listeria monocytogenes - drug effects; Onions - microbiology; Vegetables - microbiology; Encapsulation; Cyclodextrin; Antifungal; Fresh-cut produce; Escherichia coli; Listeria monocytogenes; Food safety; Allyl isothiocyanate; Vegetables; Onion; Antimicrobial agent; Antifungal agent; Fresh product; Bacteria; Models; Isothiocyanates; Enterobacteriaceae
• ISSN: 0740-0020; 1095-9998
• DOI: 10.1016/j.fm.2011.10.015

The aim of this work was to determine the antimicrobial effect of allyl isothiocyanate (AIT) entrapped in alpha and beta cyclodextrin inclusion complexes (ICs). In model experiments, AIT formulations were applied to filter paper discs fixed inside the lid of Petri dishes, where the agar surface was inoculated with the target organism (Penicillium expansum, Escherichia coli or Listeria monocytogenes). Solid phase microextraction coupled with gas chromatography was used to determine static headspace concentrations of AIT formulations. The antimicrobial effect of beta IC was determined during aerobic storage of packaged fresh-cut onions at 5 °C for 20 days. AIT entrapped in beta IC exhibited a significantly (p < 0.05) better antimicrobial effect compared to unentrapped AIT. AIT vapour concentrations in the static system were highest for unentrapped AIT followed by beta IC and alpha IC. Application of beta IC (200 μl/l) to packaged fresh-cut onions effectively decreased numbers of L. monocytogenes, which were also decreased at slower rates to undetectable levels on untreated cut onion. After 10 days, total aerobic counts were ca. 4 log CFU/g lower on onions treated with beta IC (100 and 200 μl/l) compared to untreated controls. This work demonstrates the utility of beta IC as an antimicrobial treatment with potential applications in packaged fresh-cut vegetable products. ► Inclusion complexes (IC) were produced with allyl isothiocyanate in beta cyclodextrin. ► Improved antifungal and antibacterial effects were observed for beta IC. ► Beta IC in packages of cut onions inhibited the microflora and Listeria monocytogenes. ► Beta IC may have use as an antimicrobial treatment in packaged fresh-cut produce.