Fruit growing
and viticulture of South Russia
Processing of fruit and berries production and grapes
Research aimed at improving the biotechnology of red table wines production, taking into account the characteristics of raw materials, used yeast races, region of origin, climate and fermentation conditions, is relevant. The object of research was wines from Cabernet-Sauvignon grapes of the 2019 harvest, grown on chestnut, calcareous soils of medium loamy texture of the terroir of the Mugarty village near the Mugartychay river (Kamyshchay river basin) in the Derbent region of the Daghestan Republic, and obtained at OJSC "Derbent Sparkling Wine Factory". The strains S. cerevisiae Y-4270 and S. cerevisiae D-19 were used for fermentation. The qualitative and quantitative composition of volatile substances in the wines under study was determined by gas-liquid chromatography. It is shown that "Kara-Koisu" wine obtained using the Y-4270 strain, was more aromatic due to the greater accumulation of esters and acetate. The content of ethyl acetate (by 2.4 times), ethyl lactate (on 9.9 %), and ethyl laurate, which give roundness to fruit or floral aromas, is on 29.7 % higher in the test sample (with the exception of ethyl capronate). Aliphatic alcohols formed an important basis for the aroma of wine, the total amount of which was 433.84 mg / dm3 , which is on 39.7 % higher than that in the control. Isoamyl (62.3 %), isobutyl (42.5 %), 1-propanol (31.2%), methanol (32.5 %) prevailed in the tested wines. The aromatic alcohols are twice as high in phenylethanol, which adds floral nuances to the wine. New data indicated the role of the biochemically active S. cerevisiae strain VKPM Y-4270 in the creation of dry red wines.
The change in the content of terpene alcohols in sparkling wines at the main stages of production, depending on the sugar-containing components used in champagne, has not been sufficiently studied. The aim of the work was to study the effect of sugar-containing components used in the production of sparkling wines on the accumulation and preservation of terpene alcohols in the products under production. Under the conditions of the southern coast of Crimea, the influence of sugar-containing substances in the production of Muscat sparkling wines from Muscat white grapes the content of terpene alcohols (terpenes) in them was studied. As a result of research carried out it was found that the use in the technology of wine production of the Sevastopol 23 yeast race contributes to an increase in the mass concentration of terpene alcohols in table dry and liqueur wine materials made of white Muscat grape variety in comparison with the original must. When concentrating using a vacuum of grape must from white Muscat, part of the terpenes is removed together with water, which, in general, can lead to a decrease in their content in the concentrated grape must (vacuum-must). Higher content of terpene alcohols and high tasting ratings are established in sparkling wines produced using liqueur Muscat wine material and unfermented must. A more striking" rich " bouquet, combining all the aromatic descriptors inherent in nutmeg sparkling wines, was characterized by a sample developed using unermented must. At the same time, it was found that reducing the period of post-fermented aging on yeast leads to the preservation of more free forms of terpenes. In this regard, the use of technology for preparing young Muscat sparkling wines by the bottle method is promising.
The direction of redox processes during biological aging of wine material is caused by the oxygen uptake, that is why its amount in sherry production is of decisive importance for the quality of the finished product. The aim of this work was to study changes in the volume components and physic-chemical characteristics of sherry base wines during biological aging, depending on the area of film overgrowing. The research was carried out on sherry base wines of Aligote, Rkatsiteli and Kokur Belyi grape varieties. Regulation of sherry yeast activity was carried out by introducing of tartaric acid as a metabolism inhibitor in experimental samples in the amount of 2.0 and 4.0 g/l. It was shown that the access of air oxygen at a time of biochemical transformation of metabolites provoked the non-enzymatic oxidative processes. Under the conditions of complete sherry film overgrowing in the base wines during aging, there is a decrease in the value of redox potential, optical dense D420, mass concentration of glycerin and all forms of phenolic substances, as well as a significant increase in the mass concentration of aldehydes, acetoin and diacetyl. When a discontinuous film overgrowing the increasing mass concentration of aldegides and their derivatives is observed in smaller amounts (in 1.4 and 2.6 times, respectively), in this case the values of optical dense (by 6 and 40 %), redox potential (by 6 and 17 %), and acetic acid increase. There is also an insignificant decrease in the concentration of glycerin, as a source of nutrition for sherry yeast, by 17 and 6 %, while in the control the content of the component decreases by 39 %. Under the conditions of incomplete film overgrowing on the surface of the base wines, the light fruit notes are observed against the background of aldehyde tones, as well as brown shades in color negatively affecting the tasting evaluation of the samples.
The use of secondary resources of the agrarian industry is one of the main tasks in environment protecting. The paper considers the principles of obtaining a concentrated extract of grape pomace from the red grape Granatovy variety and its use in the production of marmalade. For concentrating the extract, a rotary evaporator was used, the concentration factor was equal to 10. It was found that extract concentrating from fermented grape pomace ensures its stability and improves technological indicators. In the original extract, the content of anthocyanins is determined by photocolorimetric metod, the content of organic acids, potassium, sodium, magnesium, calcium cations by capillary electrophoresis. The extract obtained contained the toxic metals within the permissible level and had an intense red color in a weakly acidic environment, it was used as a correcting natural dye in the marmalade technology. Experimental marmalade samples were tasted. The sensory assessment procedure involved 10 specialists, including 6 women and 4 men, aged 29-45 years old (7 people), and 46-65 years old (3 people). All participants are confectionery experts, work in the confectionery industry and have professional experience in sensory analysis. Sensory assessment results were expressed on a 5-point rating scale. The best tasting characteristic was obtained for a sample of marmalade with the addition of a concentrated grape extract of 0.3% by weight, the total score was 17.5. The control sample on an artificial color substance was rated at 14.9 points. Within the framework of this article, the composition of the extract of grape pomace is analyzed, the technology for obtaining the extract and its further use in the confectionery industry is presented.
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.