ABSTRACT
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
Subject(s)
Oils, Volatile , Anti-Bacterial Agents , Hordeum , Food PreservativesABSTRACT
In this study, samples of farm shrimp species Paeneus indicus obtained from different stages of hatchery and rearing period and subsequent marketing, water and sediments of rearing farms and marine shrimp species Paeneus semisulcatuswere analysed for Vibrio spp. according to the methods described by American Public Health Association. The identified Vibrio species were Vibrio alginolyticus, V. parahaemolyticus [Kanagawa positive] and V. fluvialis. The results and detection of V. parahaemolyticusKanagawa positive [even in low proportion] in this study suggest a probable risk for health of people consuming raw or under cooked shrimp. Therefore it is recommended to pay attention to post harvest handling e.g. washing the shrimp with fresh water containing 2-7 ppm chlorine and freezing at -40 C and adequate cooking to safeguard public health. Key words:cultivated and marine shrimp, Vibrio spp., Iran
Subject(s)
Animals , Fisheries , Vibrio , Marine BiologyABSTRACT
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
Subject(s)
Plant Oils , Food Preservation , Staphylococcus aureus , Anti-Infective Agents , Preservation, Biological , TerpenesABSTRACT
To study the effect of zataria multi flora Boiss essential oil, acetic acid, temperature and storage time on probable growth of salmonella typhimurium in brain heart infusion broth. Multiple factorial analysis of bacterial growth. Salmonella typhimurium. Log probability percentage [Log P%] for growth of salmonella typhimurium was investigated in Brain Heart Infusion [BHI] broth in response to different concentration of Zataria multiflora Boiss. essential oil [0.0. 0.03 and 0.06%] and acetic acid [pH, 7.4 and 6] during 43 days storage at three temperature [35,25 and 15 [degree sign] C]. The log P% of S. typhimurium was affected significantly [P<0.05] by different concentrations of essential oil, pH levels, storage temperature and their interaction. The Log P% of S. typhimurium in BHI broth [pH, 7.4] with 0% essential oil at 35, 25 and 15 [degree sign] C were 1.07, 1.07 and 0.41, respectively. This log P% in response to 0.03 and 0.06% essential oils were -2.93, -3.24 and -4.23, and -4.23, -4.23 and -4.23, respectively. The Log P% of S. typhimurium in BHI broth [pH, 6] with 0% essential oil at 35, 25 and 15 [degree sign] C were 2, 0.76 and 1.41, respectively. This Logp% in response to 0.03 and 0.06% essential oils were -1.93, -2.59 and -4.23, and -4.93, -4.93 and -4.93, respectively. At recent conditions, growth has been completely suppressed. Based on the results of this study, Zataria multiflora Boiss. essential oil can be used as a growth inhibitor for salmonella in food products
ABSTRACT
The growing interest in substitution of chemical food preservatives, both antimicrobials and antioxidants, by natural ones has fostered research on the vegetable sources and screening of plant extracts and essential oils in order to identify acceptable natural alternatives. In order to evaluate the antimicrobial effects of different essential oils on food-borne pathogens and/or food spoilage microorganisms, first we should study them in laboratory models and then in foods. In this study Log probability percentage of growth [Log P%] of Bacillus cereus in Brain Heart Infusion broth as affected by different concentrations of Zataria multiflora Boiss. essential oil [0.0, 0.005, 0.015, 0.03 and 0.045%] during 43 days of storage at three different temperatures [30,20 and 10°C] was investigated. The Log P% of B. cereus was affected significantly [p < 0.05] by different concentrations of the essential oil, storage temperatures and combined effects of them. The maximum Log P% of B. cereus [and the day to reach the maximum probability of growth] in BHI broth with 0% essential oil at 30, 20 and 10°C were 1.46 [1], 1.46 [3] and 0.15 [28], respectively. While in BHI broth with 0.005, 0.015, 0.03 and 0.045% essential oils were 1.46 [1], -1.4693 and -3.54 [22]; 1.46 [1], 1.46 [10] and -3.85 [25]; 1.46 [16], 1.46 [16] and -4.45 [>43] and 0.15 [13], -1.85 [7] and -4.54 [>43], respectively. According to our results the Log P% of B. cereus was significantly decreased [P<0.05] by little increase of essential oil concentrations in this study. This inhibitory effect of the essential oil was also significantly increased [P<0.05], when the temperature decreased and we did not observe any growth [Log P% = -4.54] in broth with 0.03 and 0.045% essential oil during 43 days storage at 10°C