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Hydrophobic polymeric (0.45 and 0.20 μm polytetrafluoroethylene (PTFE) and 0.10 μm polypropylene (PP)) membranes were efficiently applied for cactus pear juice and sugars solutions concentration using Osmotic Membrane Distillation (OMD) process. It is reported that the PTFE membranes gave higher permeate fluxes and higher final juice concentrations. Furthermore, the filtration of raw juice prior to OMD process, the extension of the process time and the increase of processing temperature resulted in the increase of the final juice concentration. Using 0.45 μm PTFE membrane, the final concentration of the filtered juice (FJ) was 16.4 °Brix ± 0.1 (at 20 °C, after 5 h) and 23.4 °Brix ± 0.2 (at 35 °C, after 18 h). The juice quality was assessed by determining the juice viscosity, the total phenolic content, total flavonoids content, antioxidant activity and phenolic acids content. It was revealed that the physicochemical properties were preserved in the concentrated juice.

The potentially toxic metals content was determined in selected plants, used in Traditional Chinese Medicine (Angelica sinensis, Bacopa monnieri, Bupleurum sinensis, Curcuma longa, Cola accuminata, Emblica officinalis, Garcinia cambogia, Mucuna pruriens, Ocimum sanctum, Panax ginseng, Pueraria lobata, Salvia miltiorrhiza, Schisandra sinensis, Scutellaria baicalensis, Siraitia grosvenorii, Terminalia arjuna and Terminalia chebula), and some European herbs (Echinacea purpurea, Hypericum perforatum, Vitis vinifera). Samples were mineralized in a closed microwave system using HNO3 and the concentrations of Cd, Pb, Al, As, Ba, Ni and Sb were determined by ICP-MS method. Some relevant aspects of potential toxicity of metallic elements and their compounds were also discussed. Results of metal content analysis in dietary supplements available on Polish market, containing studied plants, are presented as well. The results were analyzed by principal component analysis (PCA) and cluster analysis.

The effect of amino acid peroxides, relatively stable products of irradiation of amino acid solutions, on erythrocyte components was studied. Interaction of proline, lysine, valine, and leucine peroxides (100–300 μM) with erythrocyte membranes brought about a decrease of membrane protein -SH group content and of activities of (Na + , K + )-ATPase and Ca 2+ -ATPase, and induced aggregation of membrane proteins, due mainly to the formation of interpeptide disulfides. Interaction of amino acid peroxides with hemoglobin brought about hemoglobin oxidation to methemoglobin. The effects of amino acid peroxides are similar to those of t -butyl hydroperoxide. These results indicate that peroxides of amino acid and proteins, which can also be formed under physiological conditions, may be mediators of the cellular action of reactive oxygen species.