| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 4565232 | LWT - Food Science and Technology | 2007 | 9 Pages |
The effects of different concentrations of Zataria multiflora Boiss. essential oil (EO: 0.0, 0.015, 0.03 and 0.06%), pH values (7.3 and 6.0) and storage temperatures (T: 15, 25 and 35 °C) on some growth kinetics, time-to-detection (TTD, time to the nearest visible detection) and log10 probability percentage (log P%) of growth initiation of Salmonella Typhimurium and Staphylococcus aureus in Brain Heart Infusion broth were evaluated in a factorial design study. For the log P%, the effects of another variable, storage time (D, up to 43 days) was also assessed as an additional factor. The TTD and log P % of both organisms were significantly affected (P<0.01)(P<0.01) by the values of EO, pH, T and D (just for log P %). The combinations of pH=7.3pH=7.3, T⩽35°C and EO⩽0.015EO⩽0.015 could not obviously affect the growth kinetics of the organisms in this study. Whereas, strong inhibitory action was observed by increasing of EO concentration to 0.06% at the considered pH (7.3) and T (⩽35 °C). The growth of both organisms was completely inhibited at the combinations of EO=0.06%EO=0.06%, pH=6.0pH=6.0 and T⩽25°C up to 43 days of storage. Regression equations were derived relating TTDs to EO, pH and T and log P% of both organisms to EO, pH, T and D. From these models the values of predicted TTD and log P% of S. Typhimurium and St. aureus can be calculated by any combinations of EO, pH, T and D (for log P%) within the limits studied. However, between the two TTD and log P% models obtained for both organisms in this study, the TTD models of S. Typhimurium and St. aureus showed better prediction (R2=0.951R2=0.951 and 0.978, respectively) than the log P % models of them (R2=0.852R2=0.852 and 0.804, respectively).
