Fruit growing
and viticulture of South Russia
When developing new biotechnological solutions for the agro-industrial complex, one of the key problems is the preservation of the viability of microorganisms producers of biologically active substances. Drying is the main method for stabilizing microorganisms. During the drying process, cells are exposed to damaging stress factors that reduce their viability. Projective environments protect cells from stressors. Microorganisms belonging to unstable species, when dried without the use of protective media, are subject to significant changes, accompanied not only by the loss of viability, but also by the destruction of their cellular structure. In this regard, in the course of the study, the optimal drying mode was selected, which provides for intensive moisture removal at the very beginning of drying and warming up to a temperature not higher than + 32-35 ºC throughout the entire drying time. It should be noted that the entire drying process should take no more than 30 minutes, since when drying microorganisms by the second mode with a drying duration of 37 minutes, the number of dead cells was slightly higher than with drying by the first mode. Also, during the study, a protective environment was selected, consisting of 1 % gelatin, 5 % sodium glutamate and 5 % sucrose, which showed the best results as protection of the cells of the consortium under study from the damaging drying factor and subsequent rehydration. Also, when using this protective environment, the moisture content of the consortium under study was the lowest among the selected drying options.
Fruits and vegetables are a source of an indispensable complex of biologically active substances necessary to maintain human health. According to the Ministry of Agriculture of Russia, the volume of fruit harvests for the period 2014-2019 increased by more than 10%. The seasonality of fruit and berry production is determined by the storage technology of the harvested products with the expectation of its use for a long time, which is possible in the conditions of the system of preserving the quality of raw materials both fresh and processed. It is noted that losses during storage of fresh fruit and berry products (depending on the type) can be more than 30%. A valuable alternative to polyethylene packaging is the development of films from biodegradable polymers and high-molecular compounds that are suitable for human consumption. Formed directly on the surface of fresh and processed fruits, protective biodegradable coatings often more reliably prevent oxidative and microbial spoilage due to the absence of an air layer. Bio-films are the only type of biodegradable polymer packaging that does not need individual collection and special disposal conditions. The main film-forming components for obtaining edible packages are: natural polysaccharides, substances of protein, lipid nature and their combinations. The main methods of applying film-forming components: dipping, spraying, watering and applying with a brush. It is most cost-effective for agricultural production to use the spray method, due to the economical consumption of coating and reduced labor costs. Edible polymer films prevent moisture loss, control the exchange of oxygen and carbon dioxide and give resistance to quality changes in general. In addition, attractive to the consumer edible films makes the additional presence in their composition of healthy substances, such as vitamins, minerals, bioflavonoids, all kinds of extracts, etc.
The winemaking process produces a large number of by-products (grape pomace), which contain a large number of biologically active substances. In order to preserve these substances and to slow down microbial putrefaction, grape pomace is stored dry or frozen. On this basis, the aim of the work was to study the effect of grape pomace storage methods on the polyphenol and vitamin C content. The objects of the study were grape pomace of red varieties of Cabernet and Kazachka grapes grown in the conditions of the Anapo-Taman zone. All the pomace samples were obtained after pressing, a part of which was dried at an optimum temperature of 45 ºC to preserve the structure of the grape pomace for 6 hours, and a part was frozen at minus 15 ºC, based on an analysis of the scientific literature. Analysis of the research data obtained showed that the drying and freezing processes had different effects on the change of polyphenolic substances and vitamin C contained in the pomace. The total content of polyphenols increases both during drying (10.6 % for Cabernet and 2.5 % for Kazacka) and freezing (27.7% for Cabernet and 12.7% for Kazacka). Vitamin C content decreases (dried: 26.6% for Cabernet, 37.9 % for Kazacka, frozen: 21.9 % for Cabernet, 36.6 % for Kazacka), being destroyed by temperature. Thus, freezing of grape extracts is a preferable storage method, since preservation of polyphenolic substances can increase their potential use.
Apples are the most common raw materials with the largest planting areas. Apple fruits are consumed both fresh and processed. The most popular among the population, according to statistics, are apple juices and their blends. The application of biotechnology for the intensification of technological processes in the food industry is the use of a complex of enzyme preparations in the technological process that contribute to the destruction of plant biopolymers, including polysaccharides, which account for a significant amount of dry matter. The best results in the yield of apple juice are achieved in the production of fruit juices: using pectinase, cellulase, amylase, hemicellulase and proteinase. In the laboratory of storage and processing of fruits and berries, the technological parameters of processing apple raw materials using biotechnological processes enzyme hydrolysis with preparations: Trinolin 4000, Trinolin DF, Fructocyme P6-L, Laphase have been optimized. Enzyme preparations were introduced in equal doses. All treatments were carried out under optimal conditions for the action of enzymes, recommended by the manufacturer Eurotrade. The effect of preporations on the yield of apple juice was evaluated. For laboratory experiments, the most common varieties of apples in the Kuban were selected to obtain juice: Golden Delicious and Kubanskoye bagryanoye. The effectiveness of the enzyme preparations: Fructocyme P6-L, Trinolin DF, Trinolin 4000 and Laphase was estimated by the juice yield. The control was the juice obtained under the same conditions, but without the introduction of an enzyme preparation. Technological parameters of processing of apple raw materials have been optimized: Trinolin DF, Trinolin 4000 in a concentration of 0.02 %, Laphase in a concentration of 0.02-0.03 %, Fructocyme P6-L in a concentration of 0.03 %. The fermentation time of all the studied EP is two hours at a temperature of 45 ºC for both apple samples (Kubanskoye bagryanoye and Golden Delicious varieties), the proposed apple pulp processing mode is recommended to be used to intensify the juice separation process, since the duration of the juice production process is reduced, its yield increases and the quality of the finished product improves.
The activity of oxidative enzymes peroxidase and orthodiphenol oxidase in fresh grape must has been studied. Grapes grown in the Temryuk and Anapa districts of the Krasnodar region were used. Grapes are intended for the production of brandy wine materials. The must was fermented with spontaneous microflora, the resulting brandy wine material was subjected to fractional distillation to obtain brandy distillate. It was revealed that the activity of oxidative enzymes varies depending on the grape variety and the place of its growth. There is a difference in the activity of orthodiphenol oxidase and peroxidase depending on the grape variety: in classical varieties it is less in comparison with hybrid ones. The greatest value of the activity of redox enzymes was found in the grape must of the Levokumskiy variety, regardless of its place of growth. The treatment of the must with bentonite led to a more significant decrease in the activity of oxidative enzymes in comparison with polyvinylpolypyrrolidone and clarification of the must in the cold. The most effective processing method was the joint technological treatment of grape must with bentonite and polyvinylpolypyrrolidone. The processing of the must Before its fermentation helps to reduce the activity of oxidative enzymes and to obtain brandy distillates with a harmonious combination of aroma-forming components. In brandy distillates produced from processed grape must, the concentration of acetaldehyde, acetoin, furfural, methanol, a number of higher alcohols decreases, i.e. those components that reduce the quality and safety of brandy distillates. Brandy distillates produced from processed grape must had a higher organoleptic rating.