Ileana Cocan

Chemical Composition and Antimicrobial Potential of Satureja hortensis L. in Fresh Cow Cheese

This study presents data about the chemical composition and antimicrobial effect of Satureja hortensis L. used as both dry plant and essential oil, on fresh cow’s cheese, in order to extend its shelf-life. The proximate and elemental composition of dry plant of Satureja hortensis L. highlights important level of microelements. The content of microelements increases even when small amounts of Satureja hortensis in fresh cheese were added. The addition of Satureja hortensis dry plant leads to an increase in Fe (13.46–65.54%) and Mn (8.33–88.33%) content of fresh cheese, depending on the amount of plant added. The composition of essential oil isolated from Satureja hortensis L. was analyzed by GC-MS and the main compounds found were carvacrol (19.68%), o-cymene (30.86%), and p-cymene (28.07%). In order to use Satureja hortensis L. as natural preservative in food industry, in vitro effect of plant extract and essential oil against Staphylococcus aureus Gram-positive bacteria was tested. The oil of Satureja hortensis L. showed antimicrobial activity at 0.50–1.5%, while the alcoholic extract does not inhibit Staphylococcus aureus mycelial growth. The antimicrobial effect of Satureja hortensis L. dry plant in various proportions (0.5–1.5%) and essential oil (0.1%; 0.25%; 0.5%), on fresh cow’s cheese, was assessed after 3 and 7 days by counting colonies obtained at 30°C. Results have shown that the addition of Satureja hortensis L. dry plant and essential oil led to a reduction in the total number of germs, this reduction being more significant when the essential oil was used. Regarding the effect of Satureja hortensis L. essential oil against Staphylococcus aureus inoculated in fresh cow’s cheese, the results highlight that the essential oil of Satureja hortensis L. may be a natural solution to prevent the development of this bacteria, while the ethanol extract does not prove to be effective.

Phytochemical screening and biological activity of Lamiaceae family plant extracts

The current study aimed to investigate ethanolic extracts from the following medicinal plant species cultivated in western Romania: Melissa officinalis L., Rosmarinus officinalis L. (RO) and Salvia officinalis L. (SO). Antioxidant activity, total phenolics content and a profile of the main hydroxycinnamic acids (HCAs), including caffeic, ferulic, coumaric and rosmarinic acids, was determined for each plant extract. The in vitro antimicrobial activity against four bacterial strains (Escherichia coli, Listeria-, Pseudomonas aeruginosa and Staphylococcus aureus), and the effect on cell viability in two melanoma cell lines (B164A5 murine melanoma and A375 human melanoma) was also assessed. The results indicated that total phenolics content was 73.76–274.73 mg GAE·g−1 and the antioxidant activity was 2.32–2.87 mM Fe2+·100 g−1. There was found a strong positive correlation (R=0.9691) between total phenolics content and the antioxidant activity in the investigated samples. Regarding the HCA profile obtained by high performance liquid chromatography, the results demonstrated that rosmarinic acid represents the main identified compound. The ethanolic extracts of RO and SO exhibited antibacterial activity against Gram positive and Gram negative bacteria. RO was the most effective in terms of decreasing the cell viability of murine and human melanoma cell lines, while the HCAs did not exhibit any effect on cell viability. These findings suggest that plant extracts from the Lamiaceae family may used in the clinic as natural antibacterial agents.

Airborne particulate contaminants during refrigeration of meat in controled medium.

The transfer of contamination through the airborne route is one of the most significant areas of high-care food production. The food industry specially the manufacturing of the chilled meat products strive for lower levels of the air contamination, therefore lot of experimental and numerical studies considers the concentration of airborne particulate contaminants, such as different species of food spoilage microorganism. In a food processing system concerned with efficient and duration preservation of primary agricultural produce post-harvesting/post-slaughtering, low carbonylic compounds as potential volatile metabolites generated by the micro flora present in the modified atmosphere CO2/O2; N2/O2, etc. of refrigeration areas for wholesale or pre-packaged fresh meat are of major interest together with other risk factors of consumer food safety. Some low aliphatic ketones with high volatility can be seized by smelling even at freezing temperatures in an advanced stage of accumulation. In this paper we suggest a guick method for the measurement of their concentration expressed as MEK starting with values of 1 ?g/m3 atmosphere (refrigeration environment) through periodical and/or continuous sampling through aspiration from the proximity of meat surface both pre-packed and stored in standard cells in modified atmosphere (25% CO2; 75% O2) (25% N2; 75% O2) in an ethanol solution of salicylaldehyde 10% (CAS 90-02-8) when it makes up a colorimetrable yellow-orange compound. Assessment can be done continuously in parallel with comparing the colour with a potassium dichromate scale (qualitatively) and also by reporting it to a sampling curve previously prepared (quantitatively). The specificity of the method is affected only by the presence in the refrigeration atmosphere of other toxic volatile metabolites of ketonic nature (acetone, acetoin, 2,3-butane dione).