Recovery and purification of rosmarinic acid from rosemary was performed using lab-scale electrodialysis unit. Electrodialysis of rosmarinic acid model solution was performed to validate its applicability for rosmarinic acid separation. Positive influence of ethanol addition on process performances was analysed in the experiments with dried rosemary extract. Under optimum process conditions (addition of 30% ethanol) ion flux reached 5.9 10(-1) g m(-2) min(-1), specific energy consumption was 3.9 kWh kg(-1), and current efficiency achieved 80.1%.

The aim of the present study was to test the antioxidant activity of rosemary extract and its mixture with propylene glycol on the stability of fat in butter. Rosemary extract was added at a concentration of 0.02% (w/w) and mixture of rosemary extract with propylene glycol at a concentration of 0.25% (w/w) to the cream before churning. For comparison, control samples without added antioxidant were also prepared and tested. Samples were stored at 4 °C and at 20 °C for 27 days and their peroxide values were determined periodically. The measurement of peroxide values for butter at 60 and 98 °C was also performed. Activity of rosemary extracts was compared with synthetic antioxidant BHT. The rosemary extract and its mixture with propylene glycol exhibited strong antioxidant activity in butter when added to a cream before churning and in an aqueous emulsion system of β-carotene and linolenic acid.

Methanol extracts prepared from five plant materials native to the Mediterranean area, namely olive tree (Olea europaea) leaf, St. John's wort (Hypericum perforatum), hawthorn (Crataegus laevigata), oregano (Origanum vulgare) and laurel leaf (Lauris nobilis), were examined for their phenolic components. Total phenolic content was determined by the Folin–Ciocalteu method. The content of proanthocyanidins in acid-hydrolysed extracts was determined spectrophotometrically. The contents of free flavones (apigenin and luteolin) and flavonols (kaempferol, myricetin and quercetin) were determined by HPLC analysis. The time of hydrolysis of flavones, flavonols and proanthocyanidins was optimised.Antioxidant activities of apigenin, luteolin, kaempferol, myricetin, quercetin and of plant extracts were examined. Antioxidative activities were studied in sunflower oil at 98 °C, by measuring peroxide value, and in an aqueous emulsion system of β-carotene and linoleic acid by measuring the absorbance of the sample. Among flavones and flavonols investigated, only myricetin inhibited oxidation of sunflower oil. All other flavones and flavonols showed pro-oxidative activity. Oppositely, in the emulsion system, only apigenin showed pro-oxidative activity while other flavones and flavonols and plant extracts inhibited oxidation of β-carotene.

In the paper, the extraction of antioxidants from Balm (Melissa officinalis L.) leaves with ethanol is presented. Effects of particle size, amount of solvent and temperature on the extraction rates and concentrations of antioxidants in the extracts were studied and kinetics was determined. Individual antioxidants (carnosic, ursolic and oleanolic acids) were identified by high performance liquid chromatography. Results showed that the intraparticle diffusion was the rate-governing step of the extraction process. The extractions all proceeded in three stages: an initial washing stage, a fast stage and a slower stage. Experimental extraction curves were analysed with a mathematical model derived from Fick's second law, and diffusion coefficients of the antioxidants within the particles under different operating conditions in ethanol were determined.

The efficiency of high pressure extraction in the production of oil with a high concentration of vitamin E, from seeds of Silybum marianum, was investigated. The solvents used in extraction were liquid or supercritical carbon dioxide and liquid propane. Operating parameters were 100, 200, 300 bar and 25, 40, 60 and 80°C for CO2 and 60, 150, 200 bar and 40, 60 and 80°C for propane, respectively. The influence of process parameters on the total yield of extraction, vitamin E composition and acid value of the extracts was investigated. Results were compared with those obtained for conventional extraction with organic solvents (n-hexane, petroleum ether, dichloromethane, chloroform). The mathematical model based on the adsorption–desorption equilibrium of oil from solid tissue, the diffusion of oil to the surface and mass transfer through external film into the bulk, described the experimental extraction results well.

The antioxidative activities of four natural antioxidants: rosemary extract (ROS.CON), α-tocopherol (TOC), ascorbyl palmitate (AP) and citric acid (CA) were studied in sunflower oil stored at 60° C. Among them, rosemary extract (ROS.CON) exhibited the best antioxidative activity, as determined by peroxide and anisidine value measurements. α-Tocopherol showed a prooxidative effect on stability of sunflower oil at tested conditions. The synergistic effects of α-tocopherol (TOC), ascorbyl palmitate (AP) and citric acid (CA) on rosemary extract (ROS.CON) were investigated. When combined with citric acid and especially ascorbyl palmitate, the rosemary extract showed an additive antioxidative effect, while by mixture with α-tocopherol a negative synergism was observed.

The efficiency of high pressure n-propane extraction in the production of high valuable extracts of pharmacologically active components with low concentration of pyrrolizidine alkaloids (PAs-undesired components) from Petasites hybridus has been investigated. Rhizomes of Petasites hybridus were extracted at pressures of 20 and 100 bar and temperatures of 20, 40 and 60 °C. The influence of these process parameters on the total yield of the extract and the extract composition has been determined on a pilot scale apparatus. This is one of the first publications on the extraction of medical herbs in such a big scale (1 L extraction unit) with n-propane.

A newly developed process for isolation of antioxidative components from rosemary (Rosemarinus officinalis) and sage (Salvia officinalis) with supercritical fluid as a solvent is presented. In the first stage of the process the essential oils are separated. Later at higher pressure the antioxidative components are extracted.The efficiency of antioxidative extracts, isolated from rosemary and sage, is compared with synthetic antioxidants. Higher efficiency of natural antioxidants is presented.