[Influence of lactoferrin and enzymatiс hydrolysates of cow's and mare's milk proteins on anaphylactic sensitivity and cytokine profile of rats].

The development of innovative ingredients of specialized formula for children with intolerance to cow's milk proteins requires accounting the influence of the protein component on the allergic sensitivity. The aim of the research was to study the effect of lactoferrin (LF) from cow colostrum, cow's milk protein hydrolysate (CMPH) and mare's milk protein hydrolysate (MMPH) on the severity of the systemic anaphylaxis reaction, the levels of specific IgG antibodies and cytokines in rats parenterally sensitized with ovalbumin (OVA). Material and methods. The experiment was carried out on 4 groups of 26 male Wistar rats, which were sensitized intraperitoneally with chicken egg OVA and a systemic anaphylaxis reaction was induced on the day 29 by intravenous administration of a challenge dose of the antigen (6 mg per kg body weight). LF, CMPH and MMPH were introduced into the diet in doses of 1.4-2 g/kg body weight per day (on an average 1.59±0.04, 1.53±0.05 and 1.48±0.05 g per kg body weight respectively). The content of IgG antibodies in the blood serum was determined by an indirect ELISA; the levels of cytokines IL-1α, IL-1ß, IL-2, IL-4, IL-5, IL-6, IL-10, IL-12(p70), IL-13, GM-CSF, IFN-γ and TNF-α were detected by multiplex immunoassay. Results. Dietary LF did not have a significant effect on the severity of active anaphylactic shock (AAS), concentrations of antibodies and cytokines in the blood of animals. As a result of CMPH consumption, there were no significant changes in AAS severity and IgG antibodies to OVA but significant increase in TNF-α level was observed as well as a significant decrease in IL-1α (p<0.05). In animals receiving MMPH, there were also no significant changes in the severity of AAS, but a 1.9-fold decrease in the level of IgG antibodies to OVA (p<0.001) was noticed along with a significant increase in IL-12(p70) (p<0.05) and IL-10 (p<0.10) level. Conclusion. Cosumption of LF by sensitized rats didn't significantly affect their anaphylactic sensitivity and cytokine profile, while CMPH intake induced some signs of pro-inflammatory processes. Consumption of MMPH was accompanied by the formation of an anti-inflammatory cytokine profile, which corresponds to a decrease in the intensity of the humoral immune response to the model allergen. Differences in the effects of two hydrolisates, which have similar degrees of hydrolysis, may be associated with the specific composition of glycopeptides formed during the enzymatic cleavage of milk protein produced by these two species of dairy animals.

[Development of fermented milk product based on mare milk and lactic microorganisms association].

Since ancient times, mare's milk has been widely used by many peoples. Thanks to its unique composition, it is now used in the nutrition of people with allergies to cow's milk, in the technologies of foods for special dietary uses, etc. To expand the range of products with useful properties, it is advisable to develop fermented milk products based on mare's milk. Numerous studies indicate that the use of fermented milk products provides various health benefits. And the use of probiotic cultures in the composition of starter cultures for fermented milk products allows you to add a number of functional properties to the product. However, the only fermented milk product available on the market from mare's milk is koumiss. Therefore, the development of new fermented milk products based on mare's milk is relevant and in demand. The aim of the study was to develop a fermented milk product based on mare's milk using an association consisting of yogurt starter culture and a probiotic strain of L. rhamnosus F. Material and methods. For the development of a fermented milk product based on mare's milk, the yogurt starter STBp (S. thermophilus and L. delbrueckii subsp bulgaricus) and the probiotic culture L. rhamnosus F (GenBank MN994629) from the collection of lactic acid and probiotic microorganisms of VNIMI were chosen. As a basis for the fermented milk product, mare's milk was used with the addition of dry mare's or dry cow's milk, pre-pasteurized at a temperature of 65±1 °C with a holding time of 30 min and cooled to a fermentation temperature of 37±1 °C. In the course of the work, the activity of acid formation during product fermentation, the duration of fermentation and the dynamics of the number of lactic acid bacteria and L. rhamnosus F probiotic strain during fermentation were studied, depending on the ratio of cultures in the ferment, the dose of the ferment introduced and the base for fermentation. The antimicrobial activity of the product was determined by agar well diffusion assay. Results. It was found that L. rhamnosus F has a low acid-forming activity, so the use of a combined starter culture (association) was proposed. It was determined that the addition of cow's milk powder to mare's milk positively affects the activity of acid formation; after 6 hours of fermentation, the pH value varied in the range of 4.6-4.83, and after 8 hours pH was 4.44-4.65. When dry mare's milk was added, the pH value after 8 hours of fermentation was in the range of 4.71-4.98 pH units. The influence of the amount of combined starter culture (association) and its cultures ratio, the duration of fermentation on the content of lactic acid bacteria, including the probiotic strain L. rhamnosus F in the fermented milk product based on mare's milk, was established. The largest amount of L. rhamnosus F was contained in the product fermented by 7% association with the ratio of cultures 1/4 and 1/6 and after 8 h it amounted to 7-9.5×108 CFU/cm3. Conclusion. Summarizing the results of the research, the technology of a fermented milk product based on mare's milk was developed: the amount of starter culture (associations) - 7%, the ratio of cultures - 1 part of the starter culture for yogurt and 6 parts of L. rhamnosus F (1/6), the fermentation temperature - 37±1 °C, the duration of fermentation - 6 hours with the addition of cow's milk powder and 8 hours with the addition of mare's milk powder. The developed fermented milk product has antimicrobial activity against opportunistic and pathogenic microorganisms E. coli ATCC 25922, S. aureus ATCC 6538, S. typhimurium ATCC 14028.