Relevance. Fermentation of cabbage is a common way of processing, which allows to preserve and strengthen its useful qualities. To date, breeders have proposed a significant number of varieties and hybrids of cabbage, each of which has its own individual biochemical characteristics. Traditional sauerkraut is carried out after harvest. Long storage can affect the change in the content of organic acids and sugars in cabbage.Methods. The aim of the work was to study the parameters of the fermentation process of eight varieties and hybrids of cabbage by selection in the Federal State Budgetary Scientific Institution Federal Scientific Vegetable Center by the intensity of sugar reduction, accumulation of organic acids, organoleptic parameters and activity of lactic acid microorganisms. Fermentation was carried out after a 5-month period of storage of heads.Results. The results showed that the storage period did not affect the fermentation result of most of the studied varieties and hybrids of cabbage. There are varietal differences in the initial content of mono-and disaccharides, organic acids, which affected the fermentation process. The increased content of malic acid in the variety population Podarok, F1 Severyanka contributed to the slowdown of the first stage of fermentation. Varietal features of the Parus population contributed to the slowdown of the first and second stages of fermentation, which was manifested in a decrease in the rate of destruction of sugars. Variety Zymovka 1474 in the process of processing by fermentation accumulates a significant amount of succinic acid, which can characterize its special difference among the studied varieties and hybrids. The best organoleptic characteristics were distinguished by hybrids of fermented cabbage F1 Likova, F1 Natali, F1 Mechta and F1 Snezhinka. The results of the study suggest that the processing of cabbage by fermentation should take into account its individual varietal biochemical features. This will not only preserve the valuable nutritional properties of the cabbage itself, but also strengthen them by optimizing the natural process of lactic acid fermentation. The result will be the best organoleptic effect achieved by an optimal combination of lactic and citric acids and mono-sugars.

The processes of fermentation, accompanied by the growth and development of several species of microorganisms, are often accompanied by a change of some species of microorganisms for anothers , such a complex "behavior" of microorganisms during fermentation needs to be be deeply researched. The previously used approaches of evaluation of the type of interaction of particulate monocultures in consortiums make it possible to obtain only qualitative results (synergistic, antagonistic, additive interaction) generally, without taking into the consideration the change of this interaction during the cultivation. The purpose of the research was the development of a new approach of the quantitative determination of the parameter of the interaction of microorganisms of one species with another species expressed as a continuous function determined throughout the all fermentation period. In the process of the work a two-component consortium of lactic acid microorganisms Lactobacillus brevis and Lactobacillus plantarum was selected, cultivated in two different model media as part of a study of directed fermentation of vegetable products. The work the cultivation of monocultures (included in the studied consortium) was also carried out. The performed work the original approach was developed, the approach is based on a comparison of the growth rate of the microorganisms biomass of the consortium with the calculated additive dynamics. This approach is convenient to use to identify a complex regularity of changes of the types of interaction of microorganisms in the consortium in the form of a continuous function determined during the entire cultivation period. From the point of view of the synergies of the species of microorganisms entering the studied consortium in the active phase of fermentation, the "Slava" variety turned to be more profitable than the "Parus".

Existing approaches for evaluation of types of interactions between individual monocultures in consortiums allow obtaining only qualitative results (synergistic, antagonistic, additive interaction) as a whole, without regarding to changes in the cultivation process. Therefore, the development of a new approach for the quantitative determination of this indicator as a continuous function defined during the all period of cultivation is in need. In the course of the research a two-component consortium of lactic acid microorganisms cultivated on different mediums according to directed fermentation process in vegetable products was chosen to analyze types of interaction. As a result, the an original approach that was based on comparison of grow speed of biomass of microorganisms with calculated additive curve determined by results of dynamic analysis of titre of microorganism participating in consortium in monoculture during their cultivation has been elaborated. This approach is a convenient tool to identify complex regularity in changes of types of microorganism interaction in consortium represented by continuous function defined during all cultivation period.