Primary article review and analysis

Viuda-Martos, M., Ruiz-Navajas, Y., Fernandez-Lopez, J., and Perez-Alvarez, J.. 2008. Antibacterial activity of lemon (Citrus lemon L.), mandarin (Citrus reticulata L.), grapefruit (Citrus paradisi L.), and orange (Citrus sinensis L.) essential oils. Journal of Food Safety 28: 567-576.

The article Antibacterial activity of lemon (Citrus lemon L.), mandarin (Citrus reticulata L.), grapefruit (Citrus paradisi L.), and orange (Citrus sinensis L.) essential oils is an explanation of the experiment conducted involving the testing of essential oils (EO's) from a variety of citrus sources as a means of inhibiting the growth of certain common bacteria. The author's stated purpose for this experiment was that since many consumers prefer natural based antimicrobial substances, they were testing naturally occurring EO's for their antibacterial properties. They did this by using six different strains of bacteria, grown on agar plates, and placing filter paper discs, 9mm in diameter and impregnated with between 2 and 40 L. Of EO from one of the four sources, on top of the agar. After incubating for 48 hours at a temperature appropriate for the growth of each bacteria, they measured the lack of growth of the bacteria, if any, on the agar around the paper filters. The tests were conducted three times for each bacteria and EO and the measurements were statistically analyzed using standard statistical methods.

After displaying their methods and results, the authors asserted their conclusions: grapefruit EO was most effective inhibiting the growth of three strains of bacteria, and lemon EO was most effective against the other three. Both mandarin and orange EO's were only minimally effective at inhibiting the growth of the bacteria used in the test.

The scientist's methodology and analysis of their experiment were proper and standard, especially the use of analysis of variation (ANOVA) to account for differences in variation of the same test, and Tukey's test to account for the significant differences between the different levels of concentration of EO's. Redundancy in the testing assured an accurate test. The discussion of the minimum inhibitory concentrations (MIC) was especially informative since the purpose of the study was to discover natural occurring EO's which could be used in the food industry as a means of preservation. By determining minimum amounts necessary, the scientist presented, not only the inhibitory effects of certain EO's, but also the amount which may be needed; determining whether or not the use of EO's is economical or even practical.