[The influence of the drying method for food properties and hypolidemic potential of oyster mushrooms (Pleurotus ostreatus)].

The aim of this research was to study the influence of two drying methods: freeze-drying sublimation and dry-air drying on the selected nutritional properties and hypolipidemic potential of fruiting bodies of oyster mushroom (Pleurotus ostreatus). The criteria for evaluation of the food properties were the color, the morphological structure, regidratation capacity, the total level of soluble proteins, fats, polysaccharides, free amino acids and monosaccharides. Lipid-lowering potential of oyster mushroom was evaluated by the concentration of lovastatin and the level of antioxidant activity. It has been experimentally revealed that the value of optical density of hydro-alcohol extracts of dried oyster mushrooms at a wavelength of 295 nm most clearly characterized its color which intensity was almost twice less in sublimated mushrooms, than шт the sample dried by dry-air method. Histological data showed that dry-air drying lead to the destruction of the mushroom cells and to the formation of a dense layered structure. Sublimation drying preserved the ordered cell structure and provided less deformation and shrinkage of the tissues. Using X-ray microtomography it was reported that freeze-dried mushrooms had uniform pore volume distribution. Dry-air dehydration method lead to the formation of larger cavities. The average percentage of the open pores was: 29.41±0.52% (after dry-air method), 11.10±0.41% (after freeze-drying method). Respectively the number of closed pores, which reflected the true value of porosity, was 0.99±0.01 and 1.75±0.01%. Structural differences of the samples of the dry oyster mushroom combined with their unequal hydration ability. Indicator of rehydration for oyster mushroom dried by sublimation method was 5.4±0.1, and for samples obtained by dry-air method it was 3.2±0.1. Respectively the average time of maximum water absorption was 22.7±1.8 and 45.3±2.9 minutes. It was found that the freeze-drying sublimation conditions were more conducive for the preservation of the biologically active protein and polysaccharide components of oyster mushrooms and on the other hand dry-air drying method increased the nutritional value of oyster mushrooms due to the reactions of polysaccharides autohydrolysis. The number of proteins and polysaccharides of the Oyster mushrooms samples dried by dry-air method and freeze-drying method was 72.0% and 56.0% respectively. Concentrations of free amino acids and glucose in the samples dried by freeze-drying and dry-air methods were 11.60±0.31%; 175.20±6.10 mg% and 7.00±0.28%; 144.0±5.7 mg% respectively. It has been experimentally recorded that the conditions of freeze drying were optimal in terms of ensuring the preservation of the content of natural statin and the antioxidant capacity of oyster mushrooms that provided its hypolipidemic potential. The amount of lovastatin in an the freeze-dried samples was 342±9.0 mg/kg, and was significantly higher than in the samples received by dry-air method - 190±6.0 mg/kg. The level of antioxidant activity of the oyster mushrooms samples were respectively 3.83±0.02 against 2.0±0.03 mmol/100 g. The conducted researches proved that for the production of dry oyster mushroom as a potential biologically active feedstock for the functional food products with lipid-regulating directivity the choice of the drying method had a fundamental importance.

Clinical and Pathogenetic Significance of Amylase Level and Microtomographic Index of Synovial Fluid in Various Joint Lesions.

The aim of the investigation was to study the level of amylolytic activity and microtomographic index of synovial fluid density as well as to substantiate their clinical and pathogenetic significance by identifying correlations with the known informative indicators reflecting characteristic features of the pathological process in various joint diseases. Materials and Methods: Samples of synovial fluid from 95 patients with various joint pathologies at the stage of the disease progression characterized by copious effusion into articular cavities have been examined. Synovial fluid samples obtained by knee arthrocentesis served as a material for the investigation. Conventional methods were used to determine the concentration of uric acid, inorganic phosphorus, total protein, and amylolytic activity level in the selected samples while X-ray density was identified by computed microtomography. Results: All samples of pathological joint fluid have shown a high level of amylolytic activity as compared to the synovial fluid from healthy joints. The relationship between the level of amylolytic activity in synovia and specific joint pathology has been identified. It has also been found that uric acid values, inorganic phosphorus concentrations, and total protein in various types of joint damage may influence X-ray density of the synovial fluid. Correlations between the studied indices have been established. Conclusion: New data on the level of synovia amylolytic activity has been obtained in one non-inflammatory and six different inflammatory diseases. Pathogenically determined correlation between the microtomographic index of synovial fluid density and concentrations of uric acid, inorganic phosphorus, total protein has been confirmed. Specific indicators of X-ray density of synovia in various joint pathologies as well as unidirectional and multidirectional data in comparison with the norm allow us to consider X-ray microtomography as a method that reveals additional details during investigation of synovial fluid density and brings new surrogate markers for the study of pathogenetic mechanisms of the development, differentiation, and treatment of various joint pathologies.

Synthesis of CuO nanoparticles stabilized with gelatin for potential use in food packaging applications.

In the present study, a method for the synthesis of gelatin-stabilized copper oxide nanoparticles was developed. Synthesis was carried out by direct chemical precipitation. Copper sulfate, chloride, and acetate were used as precursors for the copper oxide synthesis. Gelatin was used as a stabilizer. It was found that the formation of monophase copper oxide II only occurred when copper acetate was used as a precursor. Our results showed that particles of the smallest diameter are formed in an aqueous medium (18 ± 6 nm), and those of th largest diameter-in an isobutanol medium (370 ± 131 nm). According to the photon correlation spectroscopy data, copper oxide nanoparticles synthesized in an aqueous medium were highly stable and had a monomodal size distribution with an average hydrodynamic radius of 61 nm. The study of the pH effect on the colloidal stability of copper oxide nanoparticles showed that the sample was stable in the pH range of 6.8 to 11.98. A possible mechanism for the pH influence on the stability of copper oxide nanoparticles is described. The effect of the ionic strength of the solution on the stability of the CuO nanoparticles sol was also studied, and the results showed that Ca2+ ions had the greatest effect on the sample stability. IR spectroscopy showed that the interaction of CuO nanoparticles with gelatin occurred through the hydroxyl group. It was found that CuO nanoparticles stabilized with gelatin have a fungicidal activity at concentration equivalent 2.5 · 10-3 mol/L and as a material for food nanopackaging can provide an increase in the shelf life of products on the example of strawberries and tomatoes. We investigated the possibility of using methylcellulose films modified with CuO nanoparticles for packaging and storage of hard cheese "Holland". The distribution of CuO nanoparticles in the methylcellulose film was uniform. We found that methylcellulose films modified with CuO nanoparticles inhibited the growth and development of QMAFAM, coliforms, yeast and mold in experimental cheese sa mples. Our research has shown that during the cheese storage in thermostat at 35 ± 1 °C for 7 days, CuO nanoparticles migrated to the product from the film. Nevertheless, it is worth noting that the maximum change in the concentration of copper in the experimental samples was only 0.12 µg/mg, which is not a toxic concentration. In general, the small value of migration of CuO nanoparticles confirms the high stability of the developed preparation. Our results indicated that the CuO nanoparticles stabilized with gelatin have a high potential for use in food packaging - both as an independent nanofilm and as part of other packaging materials.