The dissertation focuses on the development of biotechnology of organic fermented milk product with high content of essential nutrients. Grass hay cattle feeding type and use of lactic acid bacterial cultures with the ability to synthesize linolenic acid c onjugates (CLA) allows to increase the content of polyunsaturated fatty acids, omega 3 acids, α linolenic acid, linolenic acid conjugates, essential aminoacids. Oligonucleotide sequences were developed to determine the ability of bacterial cultures to synt hesize CLA on the examples of Bifidobacterium breve (primer to gene RY69_RS01430) and Lactobacillus plantarum (primer to gene AKJ11_03385), and
were tested their effectiveness. Screening of fermentation preparations was carried out by polymerase chain reac tion and electrophoresis in agarose gel « Bifidocomplex » and « Lyofast LPRA » preparations were selected, which contained Bifidobacterium breve and Lactobacillus plantarum bacterias. Fermentation by the «Bifidocomplex» preparation increased CL А level on 29.5% and 16.0%, in the fermented milk product of grass fed and silage fed farms respectively as compared to the starting point . Using of the blend of cultures «Iprovit» + «Lyofast LPRA» increased CL А level on 26.3% and 11.3% respectively. Grass hay type of cattle feeding increased the level of non protein nitrogen ( on 33.8% in the pasture period and on 23.8% in the stall period) and the level of urea in milk on 40.4% in the pasture and on 14,0% in stall periods), which can adversely affect the technological properties in the manufacture of dairy products. The expediency of analyzing the level of urea in milk in the manufacture of organic fermented milk product with a high content of essential nutrients is shown.
Grass hay type of cattle feeding significan t ly (at p≤0.05) increase d of CLA level in milk on 0.79 g/100 of fat during the pasture period and by 0.59 g/100 of fat during the stall period compar ing to silage haylage feeding type. Also, the level of C16:0, C18:1 trans 11, C18: 3 n 3 was significantly differed between two feeding types , which can be used to modify the quality parameters of organic milk depending on the type of feeding.
It have been made comparisons between the methods of the biological value of milk protein evaluation by the Digestible Indispensable Score A mino A cid Score (DIAAS, 2013) and Protein Digestibility Corrected Amino Aсid Score (PDCAAS, 1991). It is shown that the difference in these approaches affects on its absolute values, which are significantly lower in the case of th e DIAAS method (0.59 for milk from farms with silage from farms with silage-haylage feeding type haylage feeding type and 0and 0,55 for milk from farms with grassfrom farms with grass-hay type) compared to the PDCAAS method (0,63 and 0,59, respectively).
A negative correlation was found between the ratio of stable carbon isotopes 13C/12C (δ13C) in the protein fraction and milk urea level, which allowed us to determine the ranges that accurately characterize the proportion of grass or corn silage in the cattle diet.
It was developed the authentication method of milk samples from farms with different feeding types by the method of principal components analysis of f the matrix of δ13C values in the milk fat fraction, levels of individual fatty acids and their ratios and the normalization of data before multivariatthe processing.
Further processing by linear discriminant analysis of the preliminary ranking matrix used in the principal component analysis, with the added indicators obtained after correlation analysis, allowed to correctly identify 87.2% of samples of organic milk and dairy products from farms with different types of feeding, regardless of the season of the year.
