[Antimicrobial efficacy of Mentha spicata essential oil and nisin in combination on Listeria monocytogenes]

Natural biopreservative are as alternative approach for controlling growth of food borne microorganisms such as Listeria monocytogenes. Essential oils [EOs] possess antibacterial properties. Mentha is one of the most common aromatic plants that widely used as medicinal and biopreservative in food. Nisin a well known antibacterial peptide to effectively antagonize a broad spectrum of bacteria, and is widely used as preservative in food. The aim of this work was to investigate the antimicrobial efficacies of nisin and Mentha spicata essential oil in combination against Listeria monocytogenes. The effects of different temperatures [4, 9 and 14°C], pH [5, 6 and 7] and NaCl concentrations [0, 1, 2 and 4%] were determinate. Description study. Essential oil content of M. Spicata had 18 components. The dominant active components were carvone [78.76%], limonene [11.50%] and menthol [1%]. Minimum inhibitory concentrations for the essential oil and nisin were 160 micro ml and 320IU/ml, respectively. A synergy of low pH values, high temperatures and high NaCl concentrations was observed. Our results found that the combination effects of M. Spicata and nisin in all experimental concentrations significantly reduced the numbers of L. monocytogenes

[Survey the of effect of zataria multiflora boiss essential oil on the growth of salmonella typhimurium in a commercial barley soup]

In spite of done improvements in slaughter hygiene and food production techniques, food safety is an important public health issue. Furthermore, the World Health Organization has recently called for a worldwide reduction in the consumption of salt in order to reduce the incidence of cardio-vascular disease. If the level of salt in processed foods is reduced, it is possible that other additives will be needed to maintain the safety of foods. Essential oils are probably one of the natural additives that can use as antibacterial additives. The aim of this study was evaluation of the effect of Zataria multiflora Boiss. essential oil on the growth of Salmonella typhimurium in commercial barley soup. At first, essential oil of Zataria multiflora Boiss. analyzed using GC/MS and the chemical components were identified. Antibacterial activity of Zataria multiflora Boiss. essential oil on the growth of Salmonella typhimurium in commercial barley soup evaluated by using different essential oil concentrations [0.0, 0.005, 0.015 and 0.03%] and two different temperatures [8 and 25°C] during 21 days. Antibacterial activity of Zataria multiflora Boiss. essential oil on the growth of Salmonella typhimurium was statistically significant [p<0.00]. The correlation coefficient of essential oil with log10 of the number of Salmonella typhimurium was -0.402. Zataria multiflora Boiss essential oil probably can used as a proper preservative against some food borne pathogen bacteria in certain foods

Effect of Zataria multiflora Boiss. Essential oil on the growth of Staphylococcus aureus in a commercial barley soup

About 30% of people in developed countries at least once a year experience a food borne disease. Therefore, there is a need for new methods to prevent the growth of food borne pathogens or decrease the number of them in foods. One of the methods is to use plant essential oils as antimicrobial additives in foods. To establish the usefulness of plant essential oils, they must be evaluated alone or in combination with other preservation factors [such as temperature, storage time and ...] first in the laboratory models and then in food model systems. The aim of this study was to determine of the effect of Zataria multiflora Boiss. essential oil on the growth of Staphylococcus aureus in commercial barley soup using different essential oil concentrations [0.0, 0.005, 0.015 and 0.03%] and temperatures [8 and 25°C] during 21 days. The effect of different concentrations of essential oil on growth rate of Staphylococcus aureus was statistically [ANOVA] significant [p<0.01]. The correlation coefficient of Zataria multiflora Boiss. essential oil with log l0 of the number of Staphylococcus aureus was -0.588. The effect of storage time on growth rate of the organism was also statistically [ANOVA] significant [p<0.05]. The correlation coefficient of storage time with log l0 of the number of microorganism used in this study was -0.2 which showed a decrease in the growth rate of the organism when the storage time was increased. In addition the correlation coefficient of storage temperature with log l0 of the number of Staphylococcus aureus was 0.449. In other words, by decreasing the storage temperature [from 25 to 8°C], the decreasing of the growth rate of the microorganism was observed. The effect of different storage temperatures and their interaction with different concentrations of essential oil on growth rate of Staphylococcus aureus was also statistically [ANOVA] significant [p<0.01]. The results suggested that the Zataria multiflora Boiss essential oil can be considered as a natural preservative in some foods