Fruit growing
and viticulture of South Russia
Processing of fruit and berries production and grapes
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.
The aim of the work is to assess the influence of natural and climatic factors the nitrogen composition of red table wines from Cabernet Sauvignon grapes growing in the Derbent District of the Republic of Daghestan. Objects of research the samples of red table wines: No. 1 harvest 2017, No. 2 harvest 2018. The wines were made at Derbent sparkling wine factory. The yeast strain S. cerevisiae VKPM Y-4270 was used for fermentation. The study of amino acids and nitrogenous substances in the wine materials was carried out using capillary electrophoresis on devices of the "Kapel 103" and "Kapel 105"series. Physical and chemical parameters were determined by standard methods used in enochemistry. The volume fraction of ethyl spitre was 11.3 and 13.0 % vol. in the studied samples, the mass concentration of titrated acids was 5.0 and 6.0 g/dm3, respectively. The concentration of nitrogenous compounds in the analyzed samples was established: the mass concentration of total nitrogen is 146 and 184 mg / dm3, ammonium ions 3.1 and 3.2 mg/dm3, and protein 8.5 and 10.1 mg / dm3, respectively. The protease activity of the S. cerevisiae strain VKPM Y-4270 was studied, it varied from 127 cu (sample Ή 1) to 138 cu (sample Ή 2). 15 amino acids were identified in the experimental samples of wine, the mass concentration of which was: sample Ή 1 4952.68 and sample Ή 2 1672.78 mg / dm3. The amino acid proline, as an important protein building material for the cell, prevailed in all samples, its amount in 2018 wine is 3.1 times higher. Of the essential amino acids in the same wine sample, an increased content of methionine, lysine, histidine, isoleucine, and tryptophan was found. The wines under experiment had a fairly high tasting rating and a high biological value.
The production of competitive geographical denomination wines, that can solve import substitution issues and improve the quality of wines, should become one of the promising direction for the development of Daghestan wine-making. In this regard, there is a need to produce the high-quality wines from grape varieties with high biological value The production of wines raising the prestige of the Republic, fixed under the term wines of protected geographical names, must also be supported, as well as the use of local grape varieties as well as raw materials for their production, along with introduced ones. It is made a comparative study of experimental samples of wine materials, obtained from grapes of local technical the Gimra Novaya, Fioletta varieties, and introduced variety of Pervenets Magaracha, grown in the Southern plain zone of Daghestan. Physical and chemical parameters were determined by standard methods used in anoxemia. The study of phenolic substances and vitamins was carried out using capillary electrophoresis on the "Kapel 104T" device. It was found that the wine material from the Gimra Novaya grape variety significantly exceeds other experimental samples in the amount of phenolic substanced (3361 mg/dm3 ), content of ascorbic (100.13 mg/dm3 ), orotic (27.45 mg/dm3 ), caffeic (29.90 mg/dm3 ), gallic acids (38.80 mg/dm3 ) and the total amount of biologically active substances (226.89 mg/dm3 ). The results of research carried out have revealed that the local grape varieties of Gimra Novaya and Fioletta have some advantages in terms of the content of biologically active substances, compared to the introduced variety of Pervenets Magaracha and can be used for the preparation of high-quality extraordinary red and pink blended wines.
Malic acid plays an important role in the addition of the taste and aroma of grape wines. Its high concentrations lead to the appearance of herbaceous tones and tones of "green acidity", sharpness and softening of taste. To reduce the concentration of malic acid it used the different methods of acid acidification. The work provides data on the effect of the combined acidization method the concentration of organic acids, potassium cations and calcium. The combined method involves reducing the concentration of wine acid with chemical reagents followed by biological acid-acidization with different strains of bacteria of apple (malolactic) fermentation. It has been established that chemical reagents help to reduce the concentration of organic acids mainly due to wine acid. At the same time, neo-antiticide and malicide were the most effective. The ensuring of wine materials with potassium and calcium cations is shown in the process of chemical acid reducing. Analysis of experimental data indicates the slow flow of the process of biological decline of apple acid in the wine materials. At the same time, more active acid-lowering took place in white wine in comparison with red wine. Among the bacteria in terms of the decrease rate in the concentration of apple acid in the white wine material stood out the strains of Vitilactic and Inobacter, which reduced the concentration of malic acid to 1 g/dm3 . The joint use of chemical and biological acid acidization helps to accelerate the reduction of the malic acid concentration in both white and red table wine material`s due to the greater accumulation of biomass of malic-milk fermentation bacteria. There was an improvement in the organoleptic properties of wine materials, and the absence of their enrichment with potassium and calcium cations.
Experimental data on the reological (viscosity-plasticity) characteristics of yeast and adhesive precipitation of wine production are presented. Their knowledge is necessary for calculating the technological equipment when designing the recycling lines. Yeast sediments obtained in the production of white and red grapes by different technologies were used as objects of the study. The effective viscosity of yeast and adhesive precipitation was determined by the Reotest-2 rotary viscosimeter with a cylindrical measuring device. Comparing the amount of plastic viscosity of yeast sediments of white wine materials of Chardonnay and Sauvignon blanc, produced using the same race of yeast, it can be noted its greater importance in Sauvignon blanc, which is associated with the accumulation of more extractive components. The greatest importance of plastic viscosity among red wines is revealed in the sediments of the Krasnostop AZOS during the pulp fermentation. Plastic viscosity of sediments precipitation was caused by the grape variety and the type of sorbent used to process wine. It was established that bentonite sediments had a large amount of plastic viscosity in comparison with gelatin sediment. The joint use of gelatin and bentonite to process wine have led to slight increase in the plastic viscosity of adhesive sediment in comparison with bentonite. When processing the wine materials, especially red ones, with polyvinylpyrrolidone together with bentonite suspension, the more dense sediments was obtained, the plastic viscosity of which had the highest values. The effect of grape variety and wine production technology the amount of plastic viscosity of adhesive sediments has been proved: with the increase in the concentration of high-molecular substances (colloids) in processed wine materials, the plastic viscosity increases.