The biological activities of extracts from skin and edible part of red onion have been investigated. Crude extracts of red onion were obtained separately with acetone, ethanol and aqueous solution of solvents. Extracts from onion edible part showed somewhat lower activity. Furthermore, high activity of skin extracts against bacteria Escherichia coli, Pseudomonas fluorescens and Bacillus cereus and against fungi Aspergillus niger, Trichoderma viride and Penicillium cyclopium was observed
The aim was to obtain extracts with high anthocyanin content, which show stability during storage and would be interesting for commercial applications as natural colorants. Single-step batch extractions were performed with ethanol, ethyl-acetate and acetone in different ratios with water as well as two-step extractions, combining SFE and conventional batch extractions. The most efficient conventional solvents in single-step extractions were mixtures of organic solvent and water at 60 °C. Pre-treatment of natural material with supercritical CO2 improved the extraction of polyphenols.
Subcritical water extraction (SWE) of phenolic compounds from pomegranate seed residues (PSR) was performed. Total phenolic content (TPC) and antioxidant capacities of the extracts obtained at different temperatures were determined, and the individual antioxidant capacities were evaluated by coupling high performance liquid chromatography with ABTS radical reaction system (HPLC - ABTS·+).
Two mathematical models, Sanchez–Lacombe equation of state and the Perturbed-Chain Statistical Associating Fluid Theory were applied for modelling the phase equilibrium for the poly(l-lactide)–CO2 and poly(d,l-lactide-co-glycolide)–CO2 systems. Aspen Polymer Plus software was used. The results suggest that both SL EOS and PC-SAFT are reliable models in describing the phase equilibrium of the PLLA–CO2 and PLGA–CO2 systems at the proposed working conditions.
The thermodynamic fundamentals of supercritical fluid extraction (SFE) are described and the environmental, health and safety benefits of using supercritical fluids are explored. Several hundred industrial-scale SFE plants are in operation worldwide for extraction of plant materials, such as hop constituents, decaffeination of tea and coffee, and separation of lecithin from oil, all high-pressure processes.