Fruit growing
and viticulture of South Russia
Grapes are a seasonal crop, and their consumption in fresh form is limited to two or three months. Extension of the period of consumption is possible by careful selection of yielding and genotypically stable varieties, the set of which would ensure an equal arrival of products in trade and processing enterprises, as well as by forming a rational logistical system of transportation and storage, which allows to prolong the storage period of grapes. To date, there are a number of technologies for grape storage, allowing to minimize the value of losses, as well as to prolong the period of storage. However, not all methods are safe for human health and their effectiveness cannot be justified. Proceeding from this, the aim of the research is to develop storage technology for table grapes, allowing to extend the storage period, using biotechnological methods, safe for human health. On the basis of the analysis of scientific and technical information sources, it was established that a promising direction is the development of storage technology with the use of film-forming films and coatings. On the basis of organoleptic biochemical, physico-chemical and microbiological studies the technology of table grapes storage with the use of film-forming coatings based on starch and gelatin and based on chitosan and sodium alginate has been developed. It has been established that storage of grapes with film-forming coatings in accordance with the developed technology has a positive effect on grape yield and reduces the value of total losses. The best indices, irrespective of the composition of the film-forming coating, showed the samples treated at the rate of 100 ml per 1000 grams of berries. The yield of marketable grapes when using the coating based on starch and gelatin increased by 29.6 %, the yield of grapes based on chitosan and alginate increased by 25.7 %.
Courgettes and scallop squash are quite important vegetable crops in the Russian Federation. For the period 2000-2020 gross yields of courgettes and scallop squash in farms of all categories increased by 10.5 %, in the commercial sector (agricultural organizations and peasant/farm enterprises) by 95.4 %. However, as objects of storage, the fruits of these crops are distinguished by thin integumentary tissues, low water-holding capacity, high respiration rate, and vulnerability to microbiological deterioration. Further complicating the organization of their storage is the fact that courgettes and scallop squash are thermophilic and get damaged by low temperature. Thus, the creation of technologies to control the loss of courgettes and scallop squash is relevant. The purpose of this work was mathematical modeling of the processes of natural weight loss of fresh courgettes during storage and the development of software for predicting losses. As objects of study, a hybrid of courgettes Iskander F1 was used. The courgettes were stored for 10 days under various conditions: the temperature varied from 7 to 15 ºC, relative air humidity - from 55 to 95 %. At the end of storage, the mass of research objects was determined. As a result of the conducted work, the dependence of the natural weight loss during storage of courgettes on such parameters as temperature and relative air humidity was revealed. The established dependence made it possible to create a mathematical model and develop software based on it, designed to predict the amount of losses depending on the aforementioned parameters. The developed application llows to optimize the storage parameters of courgettes in order to reduce losses and maximize the duration of their storage.
In recent years, many wineries have chosen to avoid using commercial S. cerevisiae strains as fermentation starters, and preferred the use of autochthonous selected strains as an oenological strategy that allows combining the industrial advantages of inoculated fermentation with the authenticity and typicality of spontaneous fermentation by native S. cerevisiae strains. One of the important tasks in the search for autochthonous strains of S. cerevisiae is the assessment of the genetic identity of strains and their genetic diversity. The interdelta genotyping method is successfully used for this purpose. The paper presents the results of interdelta genotyping of 49 autochthonous S. cerevisiae strains isolated on white and red grape varieties on the territory of the Krasnodar region, using three primer pairs δ1+ δ2, δ12+ δ2, δ12+ δ21. It was found that when primer pairs δ12+ δ2 and δ12+ δ21 were used, 14 different patterns were formed in the samples. When using the primer pair δ1+ δ2 11 patterns. With the primer pair δ12+ δ21, 5 and 6 groups of genetic similarity were formed in the studied samples, which is higher than when using other types of δ pairs. According to the dendrogram obtained from the results of the interdelta analysis and constructed using the UPGMA method, the strains were divided into 2 main groups, and the first group included only yeasts isolated on the Dostoynyi grape variety (19 out of 28 strains). The second group included 9 strains isolated on the Dostoynyi grape variety and all strains isolated on the Chardonnay grape variety, which in turn were combined into subclusters. Data of studies allow us to draw preliminary conclusions about the specificity of the genotypes of autochthonous yeasts found on the surface of white and red grape varieties.
Amino acids are the most important group of organic nitrogenous substances in grapes. In the initial period of grape ripening there are few amino acids in grapes. During ripening their qualitative and quantitative composition noticeably changes. The amount of amino acids in grapes depends on variety, climatic conditions, soil composition, ripeness at harvest, method of processing, particularly the duration of contact of must with the hard parts of the bunch and many other factors. At the beginning of alcoholic fermentation there is an active consumption of amino acids by the yeast, and afterwards, as it dies off, the yeast enriches the wine with them. These compounds influence the formation of aroma and flavor of wines, as they are the precursors of many aromatic compounds. The purpose of the study is to establish the features of the biochemical composition of amino acids in liqueur wines of the port type prepared from white hybrid grape varieties. The objects of the study were liqueur wines of port type from white technical grape varieties of interspecific origin: Kristall, Platovskiy and Stanichnyi. Wine material prepared from Aligote variety was taken as a control. On the basis of the conducted studies, it was found that the total sum of amino acids in the experimental sample prepared from the Platovskiy grape variety was significantly higher compared to the other experimental wines (2692 mg/dm3 ). Proline dominates among the amino acids of all the test samples by mass concentration, its percentage of the total sum of amino acids in the studied wines was: Aligote (control) 86,3 %; Kristall 81 %; Stanichnyi 51,4 %; Platovskiy 83 %. The highest levels of amino acids arginine (162.5 mg/dm3 ), and leucine (4.88 mg/dm3 ) were observed in the wine made from Stanichnyi. The experimental variant of the variety Platovskiy had a fairly high content of ß-phenylalanine (23.67 mg/dm3 ) compared with other, and the highest amount of valuable amino acids: tyrosine 63.07 mg/dm3 ; serine 24.01 mg/dm3 ; threonine 138.6 mg/dm3 ; ɑ-alanine 26.61 mg/dm3 . The highest glycine content was observed in the wines prepared from the varieties Kristall (7.24 mg/dm3) and Platovskiy (7.89 mg/dm3).
Studies of the economy of viticulture of the Rostov region were carried out as part of a program of research work on the creation of grape varieties with improved economic and valuable features and improving methods for assessing the economic efficiency of new grape varieties. Analysis of the dynamics of vineyard areas made it possible to establish that in 2000-2020 they decreased by 27.6% and vineyards occupy 4.2 thousand hectares, of which 76.2 % of the vineyard area in fruiting age. 56.3 % of the total area of fruiting vineyards, is occupied by classical European varieties 8.9 % autochthonous, 34.8 % varieties of Russian and foreign scientific centers of viticulture breeding, including ARRIV&W named after Y.I. Potapenko breeding 18.74%. The data of the study of sales of planting material indicate that in 2018-2020, the share of varieties of ARRIV&W a branch of FGBNU FRANZ breeding in the total sales of grafting seedlings was 5.19 %, root seedlings of the 1st grade 83.91 %, root seedlings of the 2nd grade 70.77 %. It was caused by the state of the viticulture economy, the orientation of regional wineries to autochthonous grape varieties in the production of wines, the financial situation of enterprises and farms, wine producers. The data of forecast calculations indicate a high probability of reducing the area of vineyards in the Rostov region by 2025 compared to 2021 by 1.7-4.74 %, in 2028 by 2.9-8.6 %. To preserve the vineyard area at the level of 4200-4300 hectares, it is necessary to annually lay new vineyards on an area of 122-169 hectares. This will require 291.4-455.9 thousand grape seedlings. It is also necessary to increase the budget financing of the industry to 86.7-89.0 million rubles per year.