Fruit growing
and viticulture of South Russia
In the 2016-2017 the etiology of summer grape rots affecting Muscat Blanc grapes in conditions of the Southern coast of Crimea studied. These rots are becoming more and more important economically and can lead to the loss of up to 80% of the ripening harvest. It has been demonstrated that this phenomenon is a complex one and is caused by the development of such species as Botrytis cinerea Pers., Guignardia baccae (Cav.) Jasz., Aspergillus niger Tiegh., Rizopus nigricans Ehr., Cladosporium herbarum (Pers.) Link, Penicillium sp. It was established that sour rot prevails in the structure of berry rots affecting grapes by the harvest time (the third decade of August and the first and second decades of September). We studied how various affecting Muscat Blanc grapes berry rot pathogens depend on the temperature regime and berry juice sugar content. A strong correlation was established between the intensity of oidium development and damage to the grapes caused by thrips and the level of sour rot development. Laboratory and field experiments provided data on the biological effectiveness of modern specialized fungicides in controlling the development of grape rot pathogens. Fungicides application proved insufficient in preventing harvest loss of Muscat Blanc grapes from sour rot. To effectively control this disease, it is necessary to develop a separate set of measures, including those aimed at improving the mechanical strength of the grape berry skin, prevent oidium and herbivore thrips damage to the epidermis during berry growth, limit the development of fruit flies during the ripening of grapes.
Ochratoxin A (OTA) is among the priority contaminants of grape wines. OTA has an expressed toxic (mainly with damage to the urinary system) action, associated, as a rule, with the long-term supply of toxin with food. International Agency for the Study of Cancer, OTA is classified as a substance possibly carcinogenic to human being (group 2B). The average content of OTA in wine, calculated by JECFA experts as a result of analysis of data from studies conducted in the world, was 0.32 g / kg. At the same time, a higher level of toxin (0.4 g / kg) was found in red wine than that in white wine (0.1 g / kg). Currently, Russia does not have hygienic regulations on the content of OTA in grape wines. In EU countries, the maximum OTA content in wines should not exceed 2 g / kg. The aim of this work was to study the content of OTA in grape wines, presented on the territory of Russia. The presence of ochratoxin A (OTA) Mycotoxin in 26 samples of dry, semi-sweet and dessert grape wines of domestic and foreign production, bought in a retail trade in Russia has been studied. Using the high effective liquid chromatography with tandem mass spectrometric detection, OTA has been found in 8 (31 %) from 26 wine samples studied in an amount from 0.14 to 0.64 μg / l (average content is 0.25 μg / l; median 0.21 g / l). The predominant contamination of OTA in the red wines, as well as in the semi-sweet and dessert wines is shown. The results of the study indicate the presence of ochratoxin A in the grape wines presented on the territory of Russia, that requires to exercise the appropriate control by manufacturers and supervisory authorities.
The results of the study of changes in normalized losses from the natural loss of fruit weight (NLW) during the storage of new scab immune columnar apple varie-ties of VNIISPK breeding at a temperature regime +2 ºC are presented in comparison with the Norms of natural loss of fresh potatoes, vegetables and fruits during long-term storage at bases and warehouses of different types for the second climatic group. Five varieties were studied. The variety Antonovka Obyknovennaya was taken as a control. The study revealed that the lowest losses from NLW were in the fruits of the Poezia variety 0,0299 % per day and 0,8960 % for 30 days of storage, while the total duration of storage was the least 102 days and the registration period of fruit weight loss was 88 days. The greatest losses were recorded in the fruits of the Zvezda Efira variety 0,0397 % per day and 1,1910 % for 30 days of storage, but the duration of their storage was the longest 144 days and 129 days of the registration period of fruit weight loss. Guided by the Norms of natural weight loss for apple fruit of winter varieties when they were stored for a long time in the rooms with artificial cooling in the Orel region (the second climatic group), it can be stated that NLW in immune columnar varieties goes beyond this norm. The average normative indicators for September-December are 2,0 %, while the indicators of the studied varieties were in the range from 2,6 to 5,0 %. It is prematurely to talk about the instability of the studied group of the varieties to NLW during storage taking into consideration the insufficiency of the studied indicators. It is necessary to continue the studies using other storage regimes. It is noted that with increasing periods of fruit storage increase in the losses from NLW.
Traditionally, the production of wine materials and geographic indication wines is connected to the places where the grapes are grown. Taking into account the fact that in the production of various wine-making products, the wine materials are used, the transportation of which is a costly and lengthy process, a direction involving the production of products of fermented grape from sublimated raw materials is very promising. It reduces the cost of transporting of grapes as a raw material for the food production. Our study was directed to a technological assessment of the expediency of the production of fermentation products from grapes subjected to sublimation processing. As the raw material a Cabernet Sauvignon grown in the Krasnodar Territory was used. The development of modern technologies as vacuum freeze-drying allows to significantly expand the geography of the raw materials used and to select the grapes according to the variety type and composition indicators, based on the requirements for the final product of predictable quality. The technological substantiation of the expediency of fermentation beverages production from freeze-dried grape raw material is proposed. Experimental data on sublimation dehydration of Cabernet Sauvignon grapes are presented. The modes of preparation and parameters of freeze-drying of grape raw materials, ensuring its effective use in the dried state as raw material in the production of fermentation products are presented. The technology involves the use of whole grapes. The results of a comparative assessment of physical, chemical and organoleptic characteristics of the table dry red wine and a prototype of the fermented dry material are presented. It is shown that a freeze drying provides a high level of safety of properties of both raw materials and products of its processing. One of the significant advantages of the proposed technology of preparation and processing of grapes to produce fermentation products is the ability to transport freeze-dried grapes to any point close to the consumer.
More than 800 volatile components of different classes of chemical compounds take part in the formation of wine aroma such as alcohols, esters, aldehydes, ketones, lactones, terpenes, etc. Despite a huge number of the volatile components identified in wine, formation of individual wine aroma is promoted by a certain combination of these components. In this regard, the research of interrelation between some volatile components of the aroma complex and sensory characteristics of wines are actual now. Results of studying of the qualitative composition and the quantitative content of volatile components of the aroma complex of red table wines from grape cultivar Ekim Kara from the mountain-valley seaside region of the South coast soil-climatic zone are presented in this publication. The interrelation between volatile components and various shades of wine aroma were studied. The Crimean autochthonous Ekim Kara grape cultivar doesn't have pronounced varietal aroma; using different technological methods by wine production we can get wines with aroma of various trends: berry-fruit, berry-fruit with the expressed flower shades and berry-fruit with the expressed spicy shades. This publication presents the results of study of the composition of the aroma complex of red table wines produced from Crimean autochthonous grape cultivar Ekim Kara and its influence on the formation of wine aroma shades. The distinctive fea-tures of the aroma complex of wines with the aroma of different trends are revealed. The correlation dependence between the contribution of some descriptors to the overall composition of the wine aroma and the concentration of the components of the aroma complex was established. The intensity of berry-fruit shades in the aroma increases with the increase of the concentration of pantolactone, isoamilformate and phenylethylformate; spicy shades − 3-methylthiopropanol and ethylphenyl acetate; flower heptanol and tyrosol. The increase in the concentration of phenylethanol, isobutanol, isoamylol and 2-methyltetrahydrothiophen-3-OH leads to reduction in the intensity of berry-fruit shades; ethylphenylacetate − floral nuances.