The effectiveness of the films was determined against whole and selected microbiota developed during different periods of cold storage on the surface of skinless chicken breast. Tests were conducted by using turbidimetric and agar disk diffusion methods.
“The antimicrobial edible films developed showed high effectiveness against the main spoilers developed on the surface of skinless chicken breasts cold-stored along eight days,” the authors of the study, just published in the Journal of the Science of Food and Agriculture, state.
The films based on oregano EOs show higher effectiveness than those based on clove EOs, but clove also proves highly effective, they claim.
Use of clove
In particular, they note that the literature on the use of clove as a source of antimicrobial EOs for meat products is practically non-existent. This could be due to general lack of awareness of the antimicrobial properties of clove EO, but it could also be because of the taste it gave products, they state.
“The antimicrobial edible films developed in this study inhibited the growth of the microbial populations that developed through the chicken breast storage and caused its spoilage,” the researchers conclude.
“The results of this research have direct application in the food industry to enhance the control of the development of spoilers such as Pseudomona spp. or lactic acid bacteria.”
The food industry typically combines a combination of cooling with modified atmosphere packaging to preserve fresh poultry.
New preservation technologies
New preservation technologies which have recently been investigated relate to non-thermal microbial inactivation techniques, such as high hydrostatic pressures; ionizing radiation; bio-conservation; use of natural preservatives; and new packaging systems, the paper states.
Active edible films and coatings are another method under exploration. They work mainly by controlling the release of their active agents onto the surface of food products, maintaining sufficient antimicrobial concentrations on the food surface.
Although there is evidence for the antimicrobial efficacy of edible films, most tests have been conducted under laboratory conditions with pure pathogen strains, the researchers state. Part of the aim of their study was to analyse their performance under real conditions.
Demand for use of natural antimicrobial films with essential oils was partly being driven by consumer preference for clean label, all-natural products, said the scientists.