Vol. 58 No. 2 (264) (2024)

The antioxidant (AH) properties (antioxidant activity, effective concentration, stoichiometry, and the number of reduced DPPH˙  ) of Armenian grape brandy depending on the aging period and radical scavenging kinetics were studied using DPPH assay and the steady-state kinetics method. The relationship between the antioxidant capacity and total polyphenol content was evaluated. The pseudo-first-order rate constant, which describes the main reaction between antioxidant and DPPH˙  , and the second-order rate constant were determined. It was shown that the AH properties and radical scavenging rate of Armenian grape brandy depend on the aging period noticeably for brandies aged for 3–7 years, subsequent aging shows a mild effect.

The work is devoted to a comparative study of fatty acids formation in natural and genetically modified blackberry seeds (collected in the foothill landscapes of Alaverdi Town, Republic of Armenia, and those of genetically modified blackberries (Rubus caesius L.), grown in greenhouse conditions in Yerevan City, harvest of 2023) capable of accumulating them in large quantities in order to justify the choice of the most valuable oilseed raw material for the production of natural oils that are in high demand in the food industry and cosmetology. It has been shown that the oil content of the studied genetically modified blackberry seeds is about two times higher than that of natural blackberry seeds. These seeds are the most promising oilseed raw material for the production of natural oils by the method of cold pressing that are in high demand in cosmetology, for example, for the production of moisturizing cream for hands and feet based on chemically pure glycerin.

The sorption (removal) efficiency of anionic surfactant modified natural zeolite from Nor Koghb deposit in relation to metal contaminants of water samples from Akhtala and Shnogh Rivers has been studied. It is shown that suggested anionic surfactant modified zeolites exhibit high sorption capability for metal adsorption from multi-component natural aquatic systems.

The study of the effect of millimeter range electromagnetic waves (MM EMW) on bovine serum albumin (BSA) structure at the frequencies both resonant (51.8 GHz) and non-resonant (41.8 GHz) for water has been conducted. The absorption and fluorescence spectra of non-irradiated and irradiated samples of physiological solution and BSA with exposition 60 min were obtained. It was revealed that the spectral characteristics of physiological solution did not change under the effect of MM EMW, while the analogous characteristics of BSA change relevantly. It was also shown that the absorption spectra of the irradiated samples significantly differ from those of non-irradiated protein.

The article discusses the importance and necessity of studying blood system one of the most significant functional systems of the body during hypoxia. Under conditions of repetitive (within 3 days) acute hypobaric hypoxia, shifts in the hematological parameters of rabbits were revealed. The study of physiological mechanisms and, especially, the use of preventive measures such as antioxidants can ensure the safe functioning of a body in unfavorable hypoxic conditions. The article considers the use of alpha-tocopherol as a strong immunomodulator to mitigate negative changes in the hematological system caused by hypoxia.

Lack of atmospheric oxygen (exogenous hypoxia) in residents of high mountain areas leads to functional disturbances of blood circulation, blood composition, activity of tissue respiration enzymes and resulting other biochemical abnormalities, causing a number of diseases. And the open mines operating in these regions create an unfavorable ecological environment, contributing to the deepening of functional disorders of the body among the population. Adolescents in this region are also at risk for the development of pathological processes. These risks can be reduced, and diseases can be prevented using non-drug means, using herbs with antihypoxic effects and special breathing exercises.

In this study, melanin was shown to have a bioprotective effect on lactic acid bacteria (LAB) belonging to different genera and species. In particular, melanin has been shown to increase the resistance of LAB to antibiotics. It was shown, that the effectiveness of melanin depends on the species of LAB and duration of exposure. In the case of Enterococcus faecium КE-5 and Lactobacillus rhamnosus 20-12 strains, the effectiveness of melanin is more obvious. At a concentration of 30 mg/mL, melanin reduces the cell count by 1 log unit, but it does not affect the rate of milk fermentation by LAB. In the case of two other strains, Lactobacillus acidophilus 1991 and Lactobacillus fermentum 27-2, it is less pronounced. Lactobacillus acidophilus 1991 showed the highest sensitivity, displaying high sensitivity to both the antibiotics and the indicated concentration of melanin.

The results of studying the sorption properties of bifunctional carbon sorbents obtained from dogwood seed shells are presented. It is shown that the greatest content of surface oxygen-containing groups is provided by oxidation of carbonizates by hydrogen peroxide generated in an electrochemical cell. The optimal oxidation mode was the use of 5 M sulfuric acid solution as an electrolyte, and the current density was 15 mA/cm². The sorption of Fe²⁺, Cu²⁺, Ni²⁺, Sn²⁺, Al³⁺, Mg²⁺, Ca²⁺ ions was studied under static conditions at pH 1.5–6.0. It is shown that the highest degree of extraction of these ions is observed at pH 4.5–5.0. The optimal conditions of extraction of the ions, distribution coefficients and static sorption capacities are presented. According to the distribution coefficients, the indicated ions are distributed as follows: Fe²⁺ > Cu²⁺ > Ni²⁺ > Sn²⁺ > Al³⁺ > Mg²⁺ > Ca²⁺.