Fruit growing
and viticulture of South Russia

Annotation

This article presents grape varieties with the potential for the production of cognacs in Russia. In the Russian Federation, cognacs are produced in Dagestan, the Chechen Republic, the Stavropol region, Kabardino-Balkaria, the Krasnodar region and the Republic of Crimea. There is a wide spread of soil types in the cognac production zones of Russia and climate changes, which imposes certain requirements on grape varieties for the production of cognac wine materials. Varieties for cognac production should have a high adaptive potential, environmental sustainability, stable fruiting against the background of changes in climatic conditions and give cognac wine materials with a characteristic freshness, subtle aroma, an insignificant volume fraction of ethyl alcohol at a relatively high mass concentration of titrated acids. The purpose of the research was to identify grape varieties with potential for cognac production, taking into account the established practice of using European varieties and varieties of inter-species. The objects of the study were grape varieties grown on the territory of the Southern and North Caucasian Federal Districts for the production of cognac wine materials. The research phase included the period from 2006 to 2021. 16 varieties of grapes, imported classic wine, native to Western Europe and Black Sea basin, and varieties of interspecific origin, including varieties of local breeding, characterized by high yields, resistance to widespread diseases, adaptability to local agroclimatic conditions, have been identified: Aligote, Alyi Terskiy, Bianka, Grushevskiy belyi, Yekaterinodar, Kleret, Kunlean, Levokumskiy, Novokubanskiy, Pervenets Magaracha, Plavay, Podarok Magaracha, Rkatsiteli, Saperavi, Silvaner, Stepnyak. The cultivation of these varieties will allow to obtain stable yields of raw materials of the specified conditions.

Annotation

The grape industry is among the leading in the agro-industrial complex of Dagestan. In 2021, 219 thousand tons of grapes were harvested in the republic. About 70 % of the yield is raw materials for the production of alcoholic beverages. Autochthonous varieties are often used to produce high-quality wines along with introduced grape varieties. The chemical composition of wines is an important indicator of their taste, aroma and health benefits. The presence of amino acids, especially essential ones, in natural wines indicates their functional orientation. The purpose of the research is to determine the qualitative composition and quantitative content of amino acids in experimental samples of wine materials for dry wines made from the technical varieties of the grapes Gimra Novaya, Pervenets Magaracha and Fioletta, grown on the plain in the southern viticulture zone of Dagestan. The presence of amino acids was determined in four prototypes of red and pink wine materials using the capillary electrophoresis system "KAPYeL-105", OOO NPF �LUMEX�. The method of measuring the mass concentration of proteinogenic amino acids (MVI M 04-38-2004, St. Petersburg, 2004) was used. From 7 to 11 amino acids are identified, among which partially replaceable is arginine; conditionally indispensable � tyrosine and essential � valine, leucine, methionine, tryptophan, phenylalanine. A significant amount of the substituted amino acid proline was found in red wine material from the Gimra Novaya variety � 145.3 mg/dm3 . Also, a significant amount of partially replaceable arginine was found in pink wine material from the Pervenets Magaracha and Fioletta varieties � 3.9 mg/dm3 . The composition and concentrations of representatives of amino acid pools identified in new wine materials from grapes of the local breeding varieties Gimra Novaya and Fioletta, as well as the introduced variety of the Pervenets Magaracha, grown in terroir located on the Caspian plain of southern Dagestan, indicate that these wines are functional products. The use in optimal doses of table dry wines formed from these wine materials will be useful for normalizing the activities of various systems of the human body.

Annotation

The article considers the relevance of creating an electronic database of quality indicators of authentic red wines produced in the Krasnodar region. The database contains information on the physicochemical parameters of high-quality red wines produced in the Krasnodar region, of the following categories: wines with a protected geographical indication (PGI), with the designation of the region of production; wines with a protected appellation of origin (PAO), indicating the vineyard/small area of production (municipality, rural settlement); wines with the prospect of being registered as wines with PGI or PAO. Information about the producer, the name of the wine, the varietal composition of grapes and the year of harvest is presented. The physicochemical parameters of wines are represented by the mass concentration of inorganic cations (K+ , Na+ , Mg2+, Ca2+) and anions (Cl� , SO4 2- ) � obtained using the method of high-performance capillary electrophoresis (HPCE) on the �apel 105M device (Russia); microelements (Sr, Rb, Ti) using the method of atomic absorption spectroscopy on the Kvant.Z device (Russia); phenolic substances, including anthocyanins using the spectrometry method; as well as chromatic characteristics and their calculated indicators (intensity, shade, yellowness and color coordinates in the CIELab system). The proposed database contains empirical data obtained by scientists of the scientific center "Winemaking" and the Center for Collective Use of High-Tech Equipment of the FSBSI NCFSCHVW in 2020-2022. As a result of the research and development of a database of quality indicators of authentic red wines produced in the Krasnodar region, a certificate of state registration No. 2022620910 dated 04.21.2022 was obtained. The database i s intended for the accumulation, operational search, storage and analysis of information, and also creates the basis for the development of a quality control system for wine products with geographical affiliation

Annotation

An experimental study of the behavior of dilute (c < 2×10-3, mol/dm3) aqueous solutions of malic acid in the presence of strong electrolytes in the process of continuous potentiometric titration with an electrogenerated base was performed. A phenomenological model of malic acid ionization is proposed, based on the assumption that its molecular and ionized forms exist in dimeric forms in solutions, including highly diluted ones. The proof of the correctness of the proposed model was performed by solving two mathematical models and testing them experimentally. The first classical model was that malic acid under experimental conditions is in monomeric form and in the process of titration is successively ionized by two steps. The second model was based on the fact that malic acid, like its anionic forms, is in aqueous solutions in a stable dimeric form and is titrated as a four-base acid. Ionization constants are found for each of the models, and the relationship between them is described. For the second model, it is shown that the process of ionization of malic acid in the third and fourth stages is difficult due to the fact that protons are located in a ring of carboxyl groups and are titrated much more difficult than the terminal ones, since their bond with oxygen atoms is strengthened during titration. Distribution curves of the assumed molecular and ionic forms of malic acid formed during titration are constructed, and the nature of hydrogen and intermolecular bonds is discussed. The influence of malic acid the appearance of wine titration curves was revealed. The results of comparing the ionization constants of dimernic forms of tartaric, malic, citric, formic, lactic, succinic and acetic acids found by this method are presented. The results obtained are used in titrimetry methods for evaluating the quality of grape raw and wines.

Annotation

The article presents the data on the study of amino acids of fresh and fermented juices from apples grown in the Krasnodar Territory. As a result of the studies revealed: the highest concentration of amino acids in fresh juices from Jonathan and Florina apples.The most of the amino acids, both fresh apple juices and fermented, were proline, alanine, asparagine and glycine. During fermentation, a change in the concentration of amino acids occurred: the concentration (on average 2 times) of proline, alanine, valine, glycine (except for juice from Florina variety) histidine, isoleucine, lysine, serine, methionine is increased; the concentration of asparagine, leucine, phenylalanine, cystine and cysteine is decreased. The identified trend is the same for all varieties of apples, which suggests that the physiological properties of the yeast race, but not the varietal characteristics of apples, mainly affected the change in the amino acids of apple juices during fermentation. It is known that aromatic components are formed from the amino acids of apple juices during fermentation. The aromatic substances of finished ciders were studied, among which the higher alcohols, volatile acids, esters, aldehydes, which determine a special bouquet and taste, were identified. Higher alcohols were represented mainly by isoamyl alcohol (more than 50 %), 1-propanol, isobutanol, 1-butanol, 1-hexanol. Volatile acids � for the most part, with acetic acid, propionic, butyric, isobutyric, isovalerianic and valerianic in the juices of all apple varieties had similar values. The main component (up to 90%) of esters was ethyl acetate, the content of which in apple wine materials varied from 41.8 mg/dm3 in Golden Delishes up to 128.0 mg/dm3 in Jonathan. It has been established that the composition of aromatic substances of apple wine materials, made from apples grown in the Krasnodar Territory, is significantly affected by varietal characteristics of apples.