The article scientifically substantiates and practically implements an improved three-stage technology for the synthesis of highly active precipitated silicon dioxide (white carbon black), which serves as a domestic analogue to the international standard ULTRASIL (R) VN 3. The study investigates the influence of & laquo;mild & raquo; precipitation conditions, including temperature (90-92 degrees C), sodium silicate density (1.07-1.09 g/cm3), and controlled technological pauses, on the physicochemical properties of the product. It was established that a clear separation of the nucleation (pH 11.0) and structuring (pH 10.0) stages allows for precise control of the specific surface area within the range of 150- 200 m2/g. Process scaling results on a bench-scale unit with a 400-liter reactor confirmed the stability of quality characteristics: SiO2 content >= 97 %, pH 6.2, and moisture content <= 6 %. Product testing at consumer enterprises confirmed its high reinforcing capacity in tire and rubber compounds.
In this work, the conditions for cloud point extraction preconcentration of Mo(VI) in the form of a complex with perchlorate of 7,8-dihydroxy-2,4-diphenylbenzopyrylium into the micellar phase of the nonionic surfactant Triton X-100 were investigated and optimized. It was established that the addition of sodium salicylate to the system at pH 1.7 and a Triton X-100 concentration of 0.5 vol.% induces phase separation and micellar phase formation at room temperature, which simplifies the extraction procedure and avoids additional heating. Under the selected conditions, effective preconcentration of the analyte and stable spectrophotometric response were achieved. Based on these results, a spectrophotometric procedure was proposed for the determination of Mo(VI) after cloud point extraction. The calibration plot was linear in the concentration range of 8-320 mu g/L. The limits of detection and quantification were 2.4 and 8.0 mu g/L, respectively. The developed method was successfully applied to model solutions and a biologically active supplement, and the relative standard deviation did not exceed 5.0 %.
This study aimed to develop photo-crosslinkable hydrogel compositions based on polyvinyl alcohol (PVA), the photoinitiator benzophenone (BP) and functional acrylic monomers, namely acrylic acid (AA), 2-hydroxyethyl methacrylate (HEMA), methylene-bis-acrylamide (MBA). A gradual increase in the content of gel fraction with UV irradiation time was observed for all composite films, indicating progressive crosslinking. PVA compositions with BP and AA, demonstrated the lowest content and the slowest increase in the gel fraction. The addition of MBA resulted in rapid crosslinking and the highest gel fraction content, whereas HEMA-containing compositions required longer irradiation times to achieve comparable levels of crosslinking. Water absorbability depended on both film composition and gel fraction. Films containing BP, AA, and HEMA exhibited the highest water absorbability. Compositions containing BP, AA, and MBA demonstrated the best water resistance, the highest tensile strength and hardness, and the lowest elongation at break, indicating the formation of highly crosslinked hydrogel networks.
The presented work is dedicated to the study of the possibility of developing a new type of sweet product for restaurants - a multi-component mousse of increased biological value with the preservation of high organoleptic properties of the product. Given that the products of the sweet category with a foamy structure are popular among visitors, this scientific development is relevant and timely. Cherry gum (Ukraine), collagen preparation (Ukraine), grapes, orange, walnut, sugar, cocoa powder were used in the work. The study of the viscosity of cherry gum solutions of different concentrations (1-9 %) in an aqueous medium at different temperatures and duration of exposure was conducted, which indicates the relevance of using gum as a food thickener. The influence of the concentration of cherry gum on the structural characteristics of the food system, namely its foaming ability and stability of the obtained foamed structure and density, was determined. A mathematical model of the formulation of multicomponent mousse was obtained, which relates the content of biologically valuable substances and the degree of satisfaction of the daily human need for proteins, vitamin C and calcium and the mass concentration of its components. The microbiological stability of the developed product during storage was studied. The developed mousse is recommended to be stored within 5 days after production under the conditions of refrigerated storage. The technological scheme for the production of multi-component mousse to ensure production in the conditions of the restaurant industry is presented.
Blackberry is one of the promising berry crops in Ukraine, suitable for both fresh consumption and industrial processing. Blackberry fruits of the Thornfree variety, grown in the conditions of the Central Forest-Steppe of Ukraine, are capable of forming a complex of natural biologically valuable nutrients, which are largely preserved in processed products. The purpose of this work was to experimentally confirm the possibility of preparing high-quality and biologically valuable unfortified wines from blackberries. The juice yield in laboratory conditions with heat treatment of berries was 69.6 dal/ton. Blackberry wort was prepared by adding the calculated amount of drinking water and sugar. The initial sugar content in the wort was 258 g/dm3, titrated acidity 7.0 g/dm(3). The wort was pasteurized at a temperature of 85 degrees C for 5 min, after cooling, regenerated ASD (active dry yeast) of the EC-1118 race of the Saccharomyces bayanus genus was added to the wort. The duration of wort fermentation was 42-58 days. The obtained unfortified blackberry wine materials had the following physicochemical indicators: volume fraction of ethyl alcohol 14.9 %, mass concentration of titrated acids - 6.7-7.0 g/dm(3), volatile acids - 0.4-0.6, residual extract - 21.9-28.1 g/dm3, phenolic substances - 1850-2150 mg/dm(3), ascorbic acid - 143-180 mg/dm(3). Such unfortified wine materials are suitable for the preparation of unfortified strong wines with the addition of sugar, fructose or natural honey.. The organoleptic assessment of wines with the addition of white sugar is 8.5 points, with fructose - 8.8, and with natural honey - 9.1 points. In the process of making unfortified blackberry wines, the content of phenolic substances and ascorbic acid decreases due to dilution with water and sugar and losses during fermentation. The finished wines retain up to 46 % of phenolic substances and 38 % of ascorbic acid in relation to their content in fresh fruits.
