Evaluation of antilisterial action of cilantro oil on vacuum packed ham

Cilantro oil is an essential oil preparation extracted from the plant Coriandrum sativium. A series of experiments were conducted to evaluate the ability of cilantro oil to control the growth of Listeria monocytogenes on vacuum-packed ham. The in vitro minimal inhibitory concentration for five strains of L. monocytogenes was found to vary from 0.074% to 0.018% depending on strain. Cilantro oil treatments were then tested on ham disks inoculated with a cocktail of the five L. monocytogenes strains, The treatments studied were 0.1%, 0.5%, and 6% cilantro oil diluted in sterile canola oil or incorporated into a gelatin gel in which lecithin was used to enhance incorporation of the cilantro oil. Gelatin gel treatments were also conducted with 1.4% monolaurin with or without 6% cilantro oil to determine if an interaction between the antimicrobials could increase inhibition of L. monocytogenes. Treated ham was then vacuum-packed and stored at 10 degreesC for up to 4 weeks. The only cilantro, oil treatment which inhibited growth of L. monocytogenes on the ham samples was 6% cilantro oil gel. Samples receiving this treatment had populations of L. monocytogenes 1.3 log CFU/ml lower than controls at week 1 of storage, though there was no difference between treatments from week 2 onward. It appears that immobilization of the antimicrobial in a get enhanced the effect of treatments. Cilantro oil does not appear to be a suitable agent for the control of L. monocytogenes on ham. The possible reasons for reduced effectiveness of cilantro oil against L. monocytogenes on ham are discussed. (C) 2002 Elsevier Science B.V. All rights reserved.