Iain Haysom and Kay Sharp
In this study a simple meal was prepared from raw chicken and lettuce in a manner which incorporated examples of common food hygiene malpractice. Prior to meal preparation, the…
Abstract
In this study a simple meal was prepared from raw chicken and lettuce in a manner which incorporated examples of common food hygiene malpractice. Prior to meal preparation, the chicken was inoculated with varying levels of Salmonella Typhimurium. The spread of microbial contamination (total viable counts, Enterobacteraceae counts and the presence of Salmonella species) from the chicken to sites in the kitchen was traced. Results indicate how easily bacterial contaminants from food may be spread around a kitchen. Levels of contamination on foods ready for consumption and in areas considered clean after washing up and wiping surfaces are established. These indicate that contaminants are unlikely to be removed from some sites unless cleaning procedures are rigorous.
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Clem Maidment, Allan Dyson and Iain Haysom
This paper is aimed at food science or biology students planning a practical independent study into the antimicrobial properties of spices and academic staff wishing to develop a…
Abstract
Purpose
This paper is aimed at food science or biology students planning a practical independent study into the antimicrobial properties of spices and academic staff wishing to develop a straightforward and reproducible practical activity.
Design/methodology/approach
Disc‐diffusion assays are used to investigate the antimicrobial activity of cinnamon and cloves against two bacteria Escherichia coli B and staphylococcus albus and a yeast Saccharomyces cerevisiae. Aqueous and alcoholic extracts of the spices and alcoholic extracts of their essential oils are examined. Minimum inhibitory concentrations of alcoholic extracts of both spices and oils are also determined.
Findings
Both spices demonstrated microbial inhibitory effects; alcoholic extracts had greater activity than aqueous extracts. Additionally, essential oils had greater activity than the spices. Minimum inhibitory concentrations were smaller with the oils than with the spices.
Research limitations/implications
Although the research for this paper involved just two spices, such is the size of the plant kingdom that there are wide opportunities for further investigations using this procedure.
Practical implications
Disc‐assays were found to be a simple, cheap and reproducible practical method. For this paper, micro‐organisms available for educational purposes were used; however, other organisms could be investigated depending upon available microbiological expertise and facilities.
Originality/value
The results demonstrate that the antimicrobial effects of spices and particularly their essential oils can be examined using disc‐diffusion assay. The method provides many opportunities for student investigation.