No abstract

This study reports the effect of antioxidant fractions from rosemary (Rosmarinus officinalis), sage (Salvia officinalis), thyme (Thymus vulgaris) and hyssop (Hyssop officinalis) on the oxidative stability of sunflower oil at elevated temperature. In order to isolate antioxidant fractions, the method of fractional supercritical extraction with carbon dioxide at 35 MPa and 100 °C was applied. Antioxidant fractions were added to sunflower oil at concentrations of 200 mg/kg oil and the samples were stored in an oven maintained at 98 °C. The antioxidant activity of the extracts was determined by measuring peroxide values (PV). Among investigated extracts, the rosemary extract was most effective on retarding lipid oxidation of sunflower oil. The antioxidant activity of the extracts was compared to the activity of butylated hydroxyanisole (BHA) and a commercial rosemary extract Flavor' Plus. On the basis of PV assay, the antioxidant activity of the investigated plant extracts after 12 h of storage at 98 °C followed the order: rosemary extract > BHA > sage extract > Flavor' Plus > thyme extract > hyssop extract.

The aim of the present study was to isolate and characterize antioxidant extracts obtained from dried leaves of rosemary (Rosmarinus officinalis L.) and sage (Salvia officinalis L.), originating from the southern Balkan Region. The antioxidant fraction was isolated from the plant material by supercritical carbon dioxide (SC-CO 2 ) fractional extraction under a pressure of 30 MPa and at temperatures of 40 and 100 °C. In the present study, kinetic data and yields of antioxidant extracts obtained from dried leaves of rosemary and sage under different conditions were determined. Electron spin resonance (ESR) spectroscopy assay on the ability of the extracts to scavenge stable 2,2--diphenyl-1-picrylhydrazyl (DPPH) free radicals and reactive hydroxyl radicals during the Fenton reaction trapped by 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) showed that the investigated extracts had antioxidant activity comparable to that of butylated hydroxyanisole (BHA) and commercial rosemary extract. The antioxidant fractions isolated at the higher temperature had higher antioxidant activities. A tentative analysis of the chemical composition of the antioxidant fractions obtained at the higher temperature was accomplished by LC-DAD and LC-MS analytical methods. Abietane-type diterpenoids, flavonoids and fatty acids were identified in the SC-CO 2 extract of rosemary and sage.Циљ овог рада био је изолација и карактеризација антиоксидативних екстраката рузмарина (Rosmarinus officinalis L.) и жалфије (Salvia officinalis L.) са подручја јужног Балкана.

This paper shows the results obtained in field analysis performed at the Tamiš River, starting from the settlement Jaša Tomić (the border between Serbia and Romania) to Pančevo (the confluence of Tamiš into the Danube). The Tamiš is a 359 km long river rising in the southern Carpathian Mountains. It flows through the Banat region and flows into the Danube near Pančevo. Over the years, the water quality of the river has severely deteriorated and badly affected the environment and the river ecosystem. In situ measurements enabled determination of physico-chemical parameters of water quality of the Tamiš River at every 400 m of the watercourse, such as: water temperature, pH value, electrical conductivity, contents of dissolved oxygen and oxygen saturation. The main reason of higher pollution of Tamiš is seen in connection to DTD hydro system. Sampling was performed at 7 points with regard to color, turbidity, total hardness, alkalinity, concentration of ammonium nitrogen, nitrite nitrogen, nitrate nitrogen, iron, chlorides and sulphates in samples. The aim of the present work was to evaluate water quality in the Tamiš River taking into account significant pollution, which originates from settlements, industry and agriculture, and to suggest appropriate preventive measures to further decrease the pollution of the river's water.