A Weibull model to describe antimicrobial kinetics of oregano and lemongrass essential oils against Salmonella Enteritidis in ground beef during refrigerated storage

• Published in: Meat science 2013-03, Vol.93 (3), p.645-651
• Main Authors: de Oliveira, Thales Leandro Coutinho, Soares, Rodrigo de Araújo, Piccoli, Roberta Hilsdorf
• Format: Article
• Language: English
• Subjects: Animals; Anti-Bacterial Agents - pharmacology; Cattle; Cymbopogon - chemistry; Cymbopogon citratus; Food Microbiology; Food safety; Food Storage; Foodborne; Meat - microbiology; Microbial Sensitivity Tests; Models, Biological; Oils, Volatile - pharmacology; Origanum - chemistry; Origanum vulgare; Refrigeration; Salmonella enterica Enteritidis; Salmonella enteritidis - drug effects; Weibull model
• ISSN: 0309-1740; 1873-4138
• DOI: 10.1016/j.meatsci.2012.11.004

The antimicrobial effect of oregano (Origanum vulgare L.) and lemongrass (Cymbopogon citratus (DC.) Stapf.) essential oils (EOs) against Salmonella enterica serotype Enteritidis in in vitro experiments, and inoculated in ground bovine meat during refrigerated storage (4±2°C) for 6days was evaluated. The Weibull model was tested to fit survival/inactivation bacterial curves (estimating of p and δ parameters). The minimum inhibitory concentration (MIC) value for both EOs on S. Enteritidis was 3.90μl/ml. The EO concentrations applied in the ground beef were 3.90, 7.80 and 15.60μl/g, based on MIC levels and possible activity reduction by food constituents. Both evaluated EOs in all tested levels, showed antimicrobial effects, with microbial populations reducing (p≤0.05) along time storage. Evaluating fit-quality parameters (RSS and RSE) Weibull models are able to describe the inactivation curves of EOs against S. Enteritidis. The application of EOs in processed meats can be used to control pathogens during refrigerated shelf-life. ► Weibull model described the survival curves of S. Enteritidis exposed to EOs. ► The Minimum Inhibitory Concentration of EOs on S. Enteritidis was 3.90µL/ml. ► EOs in ground beef reduced S. Enteritidis population during refrigerated storage. ► EOs combined with refrigeration represents a feasible preservation alternative.