Fruit growing
and viticulture of South Russia
Yakuba Yuriy
Articles in journal: (total 30)
This article presents the results of studying the physicochemical indicators of the cognac distillates quality with typical organoleptic properties, the composition of volatile components determined by gas chromatography and phenolic, furan compounds (aromatic aldehydes and acids) controlled by the method of highly efficient capillary electrophoresis. The ranges of criterion components and calculated indicators, characterized genuine high-quality cognac distillates, have been clarified. It was noted that in 10 % of aged cognac distillates, the mass concentrations of higher alcohols in terms of isoamyl alcohol and the mass concentrations of medium esters in terms of ethyl acetate exceeded the norms established by the interstate standard of technical conditions were exceeded and have had a maximum value of 800 mg / dm3 bsp. and 350 mg / dm3 bsp. accordingly, also the mass concentration of the total extract in all genuine cognac distillates did not exceed 6.5 g / dm3 . The ranges of calculated parameters for aged cognac distillates were found, such as the ratio of the mass concentrations of isoamyl alcohol / isobutyl alcohol from 2 to 6.5; mass concentration ratio lilac aldehyde / vanillin, not less than 1.5; mass concentration ratio lilac aldehyde / lilac acid, no more than 3.5; the ratio of mass concentrations of vanillin / vanillic acid, no more than 4.5; the ratio of mass concentrations of tannins / total extract, no more than 0.5. The obtained and refined databases of the qualitative and quantitative composition of volatile components and aromatic aldehydes and acids will make it possible to control the quality, confirm the authenticity and identify the signs of cognac distillates falsification, in particular, to establish the substitution of raw materials and the use of grape distillates (alcohols), violation of the distillation regimes and the aging process of cognac distillates in case of contact with oak wood.
The article presents the results of studying the quality indicators of wine alcohols, distillates and wine material from various grape raw materials to ground the possibility of developing a technology of high-quality wine spirits, including the processing of fresh grapes for wine materials without sulfitation and the use of enzyme preparations, and clarification of grape must by sedimentation, distillation of wine materials and rectification of the obtained distillates using the modes that allow to obtain wine alcohols with a strength of at least 94 % vol. It was found hat the yield of grape must of table grape varieties is low 70.8 dal out of 1033 tons of grapes. In an dry wine material from table varieties, the mass concentration of volatile acids exceeded the maximum permissible limit 1.60 g/dm3 . It is noted that during distillation of wine materials, the strength of distillate obtained is directly proportional to the volume fraction of ethyl alcohol of the original raw material and it was 31.9 % vol. (table grapes) and 39.5 % vol. (Crystal). Analysis of the volatile components of distillates and wine alcohols showed that the mass concentrations of the compounds analyzed in the wine alcohols are directly proportional to their content in the corresponding distillates; there is also a positive trend in reducing undesirable components in the rectificate produced. The selected rectification mode made it possible to reduce the amount of higher alcohols by 1.5 times for the Crystal variety and by 4.7 times for the table varieties. The content of esters in wine alcohols increased in 2-2.5 times mainly due to ethyl acetate, the boiling point of which is close to the boiling point of ethanol. It is shown that to obtain high-quality wine alcohols, it is advisable to use the substandard grapes both table varieties and technical varieties as raw materials.
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.
The content of free amino acids in the wines is closely connected with their quality, technology of their preparing and as a result - with their nature. However the attempts undertaken earlier to define interrelation between the content of free amino acids and authenticity of wines have led to inconsistent results. Improvement of analytical techniques of definition of an arginin, proline, treonin in the fruits, juice and natural wines by means of a capillary electrophoresis is the actual and timely task. The complexity of biochemical composition of fruits, grapes and products of their processing, in particular of grapes wines is discussed in this article. The composition of grapes wines differs in the considerable variety of components reaching 800. The existing problems of control of quality and natural composition of wines, in particular of definition of amino acids content are estimated at them. As a result of systematic of the analysis conditions the methodical approach to definition of amino acids in the products of fruits and grapes processing with use of a capillary electrophoresis is offered. In the course of carrying out of experiment the optimal composition of the electrolyte solution for the separation of model mix of amino acids and their definition in the studied samples is chosen. The time of migration of the interesting component, the observed mobility of an ionic form of substances and other parameters were used as the main criterions of an assessment of the analysis quality. The optimization of analysis modes taking into account the influence on the separation of other substances of studied objects is executed. Statistical processing of the data obtained in the experiments allowed to establish a variation of mass concentration of proline which for natural white wines changes within 400-1000 mg/dm3, and for natural red wines it changes from 600 to 2000 mg/dm3. These indicators for the raw materials can be a little expanded.
Possibilities and new methodical approaches of the analysis of wine production by means of capillary electrophoresis and gas chromatography are considered. The current Standards, providing control in wines of organic acids, dyes and preservatives are discussed. Methodical decisions for definition of glucose, fructose, sucrose and general phosphorus in wine production are offered by method of capillary electrophoresis