An insight into chemical composition and bioactivity of 'Prokupac' red wine.

Autochthonous variety 'Prokupac' (Vitis vinifera L.) red wines with the addition of selected aromatic herbs (Artemisia absinthium, Cinnamomum zeylanicum, Glycyrrhiza glabra and Pimpinella anisum L.) were evaluated for chemical composition and biological activity. Furthermore, their polyphenolic profiles were determined by HPLC-DAD. While total phenolic (TPC) and flavonoid (TFC) contents, along with antioxidant activity, were significantly higher in all examined wine samples, the content of total anthocyanins was decreased, compared to a pure 'Prokupac' wine, used as the control one. On the other hand, 'Prokupac' wines with the addition of cinnamon (S. zeylanicum) and wormwood (A. absinthium) displayed highest antioxidant (EC50, 0.021 ± 0.001 mg/mL) and antibacterial (Enterococcus faecalis, MIC/MBC 15.63/62.50 µL/mL) activities, respectively. The study showed that 'Prokupac' wine with the addition of cinnamon was significantly enriched both with TPC and TFC, compared to control wine (p < 0.05), which may contribute to its market potential.

Ultrasound-assisted extraction of total phenols and flavonoids from dry tobacco (Nicotiana tabacum) leaves.

Yields of extracted substances, as well as total phenol and flavonoid compounds obtained by classical and ultrasonic extractions from dry leaves of two tobacco types (oriental and Virginia) by two different solvents (acetone and methanol) at two operating temperatures (25 and 40 degrees C) were compared. The yield of extractive, as well as total phenol and flavonoid compounds depended on the type of solvent, operational temperature and the tobacco type. The importance of these factors was assessed using 2(4) full factorial experiments without replication.

Modeling the kinetics of calcium hydroxide catalyzed methanolysis of sunflower oil.

The kinetics of Ca(OH)(2)-catalyzed methanolysis of sunflower oil was studied at a moderate temperature (60 degrees C), a methanol-to-oil molar ratio (6:1) and different catalyst amounts (from 1% to 10% based on oil weight). The methanolysis process was shown to involve the initial triglyceride (TG) mass transfer controlled region, followed by the chemical reaction controlled region in the latter period. The TG mass transfer limitation was caused by the low available active specific catalyst surface due to the high adsorbed methanol concentration. Both the TG mass transfer and chemical reaction rates increased with increasing the catalyst amount.

Impact of carboxymethylcellulose on morphology and antibiotic production by Streptomyces hygroscopicus.

A chemically defined media consisting of carboxymethylcellulose (CMC) was developed to maximize the production of antibiotics, hexaene H-85 and azalomycine, by Streptomyces hygroscopicus CH-7. The production of antibiotics by filamentous organisms is often dependent on the morphology and size distribution of the pellet population within the culture. By adding the polymer to the fermentation medium, the growth was changed from a single large glob to small reproducible pellets, and wall growth was diminished to a minimum. Maximum concentrations of hexaene H-85 (146.7 mg/dm(3)) and azalomycine (188.6 mg/dm(3)) were reached at 3.0% and 1.0% (w/v) CMC, respectively.

Kinetics of sunflower oil methanolysis at low temperatures.

The kinetics of the sunflower oil methanolysis process was studied at lower temperatures (10-30 degrees C). The sigmoidal kinetics of the process was explained by the mass transfer controlled region in the initial heterogenous regime, followed by the chemical reaction controlled region in the pseudo-homogenous regime. A simple kinetic model, which did not require complex computation of the kinetic constants, was used for simulation of the TG conversion and the FAME formation in the latter regime: the fast irreversible second-order reaction was followed by the slow reversible second-order reaction close to the completion of the methanolysis reaction. The mass transfer was related to the drop size of the dispersed (methanol) phase, which reduced rapidly with the progress of the methanolysis reaction. This was attributed to the formation of the emulsifying agents stabilizing the emulsion of methanol drops into the oil.