The study is focused on cultivar persimmon fruits (Diospyros kaki L.) of “Khachia” variety, which is characterized by high sugar concentration, rendering it a viable candidate for the production of alcoholic beverages. During the wine material preparation phase, persimmons were meticulously sectioned into fragments measuring between 0.8 and 1.2 cm. Subsequent to this partitioning, citric acid at a concentration of 5 g/l was added and a pure strain of Saccharomyces Cerevisiae yeast was added representing 4% of the total volume of the mixture. This mixture was then subjected to heat treatment under various conditions. The experimental outcomes demonstrated that macerated persimmon pulp, after being subjected to a thermal hold at 80°C for a duration of 20 minutes and subsequently cooled to 24°C, facilitated the initiation of alcoholic fermentation in the extracted juice (referred to as 'persimmon sweet'). This enhancement in fermentability can be attributed to the observed reduction in pectin and tannin levels, as well as a decrease in the viscosity of the liquid phase. Moreover, a significant increase in juice yield was recorded, rising from 40.50% in the unprocessed state to 63.40% post-treatment. The wine substrate produced exhibited favourable attributes, including reduced levels of soluble solids (3.52%), sugars (0.20%), and volatile acidity (0.24%). The persimmon-derived alcohol contained only negligible concentrations of methanol. The study ascertained that to achieve alcohol with optimal quality parameters from persimmon fruits, preliminary treatment protocol is essential. This protocol necessitates a sequence of operations: mechanical maceration, thermal application, holding period and subsequent cooling. © 2024 Bull. Georg. Natl. Acad. Sci.

Abstract The gorge of the Ajaristskali River and its surrounding areas are important habitats for biodiversity. The territories adjacent to the gorge are a refugium of tertiary moisture-loving Colchis relic forest ecosystems, which have been awarded the status of a UNESCO World Natural Heritage Site. Ongoing work on the construction of a cascade hydroelectric power station in the gorge poses a risk of loss of the natural habitats. The article presents studies of assessing the ecological state of forest ecosystems in locations: Shuakhevi settlement, Shuakhevi water intake and Shuakhevi hydroelectric power station (HPP). In order to evaluate the current ecological state in the Ajaristskali gorge, the phytoextraction capacity of the dominant tree species forming the main natural forest in this area was studied. The alkalization of the soil samples taken from the Ajaristskali gorge was observed at the Shuakhevi HPP intake and Shuakhevi HPP. The soils are poor in total humus and nitrogen evidencing their decreased fertility. Data of the soil pollution hazard ratio show that the hazard of pollution with heavy metals, As, Ba,Cd, and Pb, exceeds 1-near Shuakhevi HPP intake and Shuakhevi HPP; pollution with Mo, Zn is observed at Shuakhevi HPP location; and Mn p ollution is observed at all three locations. Based on the calculation of biological absorption coefficient of heavy metals, we have identified the dominant tree species forming the main natural forests on the study sites, whose vegetative parts have a good phyto-extraction ability for toxic elements. Such plants are: pine (needles), oak (leaves), and alder (leaves).