No 8 (2018)

Recently the trend of increasing the cases of contamination with toxin forming micettes has been noticed. Toxins forming moulds are detected at microbiological examination of foods, feeds as well as different raw materials received from the agricultural animals. To isolate and cultivate the moulds the agar media are used, and for identification - morphological signs and tests (pigments formation, conidia and gifs, secondary metabolites) allowing to determine species.

Investigations of the fermentative lactose hydrolysis in milk have been carried out using different fermentative preparations to determine duration of fermentation and quantity of the preparation Aspergillus oryzae needed for receiving low lactose milk with the aid of the refractometry method of the lactose mass share determination. Dependence of the lactose mass fraction changes in milk on the time of fermentative hydrolysis was established. Changes of the mass share of lactose depending on the quantity of Aspergillus oryzae have been studied. The dose of the preparation Aspergillus oryzae and time of fermentation need for low lactose milk receiving have been established on the base of the analysis made.

The article presents the results of study of the feijoa jam effects on the consumer properties of a new fermented milk product. The organoleptic and rheological values of fermented milk product samples were studied during the experiment. The addition of the proposed flavor to the mixture should be accompanied by simultaneous introduction of a stabilizer (starch, for example). In this case, it is possible to predict the desired acidity increase and control the dynamic viscosity value of the samples in the range of 10-22 Pas. Manufacturing of the product by the offered technology allows improve organoleptic (smell, taste, consistency, appearance) and rheological indicators, to increase its consumer appeal.

The information on the functional properties of chitosan and its derivatives, including succinate of chitosan, which is the salt of deacetylated chitin and succinic acid, has been studied. The relevance of the subject is related to the possible use of chitosan succinate as a functional supplement in the composition of the popular fermented milk product - kefir. Effect of chitosan succinate on the antibacterial property of the natural symbiosis of microorganisms of kefir grains in relation to the collection test-cultures: E. coli, S. aureus, Cl. difficile, S. thyphimurium was studied in vitro. Besides, results connected with dynamics of yeast and kefir grains during fermentation and ripening in the presence of chitosan succinate are presented.

The article is a continuation of the publication of the results of the study «Improvement of the efficiency of the curds whey membrane processing» («The Dairy Industry» № 6, 2018). Further processing of curds whey enriched with stevia extract into glucose-galactose syrup allows to increase efficiency of the technological operation - baromembrane separation. To find principle regularities of lactose hydrolysis in the preliminary concentrated and demineralized curds whey permeate the preparation «Lactazar» produced in our country (with optimum at the pH 3-5) was applied. For determination of the optimal values of the principle parameters of the enzyme work recommendations given in the producer’s instruction (JSK «Farm-standart-Leksredstva», Kursk) were used. Analysis of the data given in the results of the study the conclusion can be made that the main quality indices of the glucose-galactose syrup received from the preconcenrated and demineralized permeate of the whey enriched with stevia extract meet all the requirements of the existing regulating documentation (TU 9229 022 00437062-2009). Microbiological characteristics correspond to the requirements given in the SanPin 2.3.2.1078-01 and referring to the concentrated and dry concentrates.

A new technological solution for the enrichment of kefir with microparticulate of curds whey proteins has been developed. Increase of the mass fraction of the microparticulate facilitated intensification of the ripening and fermentation processes, activated synthesis of kefiran by microorganisms of the kefir grains, increased antagonistic activity of the yeasts against pathogenic microorganisms. The enriched with microparticulate kefir was characterized by the standard quality indices. The technology of the developed product consists of the standard sequence of operations and is supplemented with the stages of the whey proteins microparticulate obtaining.

Milk products that quickly spoil are usually carried to consumers in small batches. As far as rather often it is impossible to make packets of the products ordered the packets are loaded and unloaded from refrigerators manually and these operations take much time. As a result temperature fluctuation on the surface of the products with limited shelf life are often observed during the whole cycle of transportation inside the town.

The effects of different temperature regimes on the content of dry substances at the cryoconcentration of skim milk has been investigated. The cryoconcentration was carried out in a separate freezing installation of the capacitive type at temperature range from minus 2 to minus 8 °С with intervals of 2 °С. According to the results of experimental studies, a regression equation was obtained to determine the mass fraction of solids in the concentrates of skimmed milk depending on the temperature and duration of freezing. It was found that the duration of cryoconcentration in the investigated temperature ranges should not exceed 2- 2,5 hours. The optimal temperature of cryoconcentration that allows to get the best ratio of the degree of concentration and the duration of separating freezing is minus 4 °С. Recryoconcentrating of crystallizates allows to reduce losses of dry substances, and hence increase the degree of skimmed milk concentrating.

The items of leucosis monitoring in the cattle, complex solution of the problem of improving health situation of the cattle herds with leucosis including most important preventive measure have been considered.