Study of Fatty-acid Composition of Goat and Sheep Milk and Its Transformation in the Production of Yogurt

The information on the structure of fatty acids is crucial for the production and promotion of goat and sheep milk in the manufacture of dairy products. The fatty-acid profile of milk fat can affect the nutritional value and market value of dairy products. The purpose of the research is to study the properties of fatty-acid composition of goat and sheep milk and its transformation in the process of yogurt production. The study of fatty-acid composition was performed using the method of gas chromatography. The milk of goats of Zaanen breed and sheep of North Caucasian breed, as well as yogurt produced from a mixture of goat and sheep milk in a ratio of 1:1 have become the objects of the study. It was found that goat’s milk contains 12% less saturated fatty acids than sheep’s milk. Oleic, stearic and palmitic acids are the main fatty acids found in the fat phase of milk and yogurt production. Changes in the concentration of individual fatty acids during milk processing and in the period of yogurt storage were noted. As a result of maturation and seven-day storage, the amount of saturated fatty acids in yogurt increased by 5% compared to the original milk mixture. The content of polyunsaturated fatty acids in yogurt decreased by 19.27 %. The highest ratio value of hypocholesterolemic and hypercholesterolemic fatty acids was noted in goat milk. It is proved that goat milk is characterized by the most acceptable fatty acid composition in terms of healthy nutrition and prevention of atherosclerosis and thrombosis. A tendency to reduce the amount of monounsaturated and polyunsaturated fatty acids, with a simultaneous increase in the content of saturated fatty acids is noted in the process of yogurt production and storage. It was found that the production of yogurt with the use of goat’s milk in the mixture allows reducing the values of atherogenicity and thrombogenicity indices. The results of the study provide an information basis for the production of qualitatively new fermented milk drinks with a fatty-acid profile favorable for human health

Influence of the maturation process on the sheep's milk of Camembert cheese fatty acid profile change

The aim of this research was to study the fatty acid composition of Camembert cheese fat phase. The object of the research was the sheep’s milk Camembert soft cheese. The Camembert soft cheese was made from sheep’s milk pasteurized at 63∘C for 30 minutes before production, using cultures Penicillium camemberti, Geotrichum candidum, as well as Lactococcus lactis, Lactococcus cremoris, Lactococcus diacetylactis, Leuconostoc mesenteroides ssp. cremoris. The study of the cheese fatty acid composition during maturation was carried out using the gas chromatography method in accordance with the state industry standard of the Russian Federation 32915-2014 ”Milk and dairy products. The determination of fatty acid composition of the fat phase by gas chromatography”. The fatty acids profile in the process of cheese maturation changed significantly. There was an increase in the short chain fatty acids concentration: oil (C4:0) kapron (C6:0), capryl (C8:0). A change in the lauric acid content (C12: 0) and myristic acid (C14: 0) showed a similar trend but with less dynamics. On the 14th day of maturation, the concentration of lauric acid (C12:0) increased by 30%, myristic acid (C14:0) – by 13%. At the beginning of the maturation period, the C18:1n9t isomer consisted about 70% of the total fatty acid trans-isomers. During maturation, the concentration of C18:1n9t decreased by 98%. It was found that, regardless of the maturation period, fatty acids C10: 0, C14: 0, C16: 0, C18: 0, C18: 1 t11 and C18: 1c9 consisted about 73% of the total fatty acids. There was a decrease in the concentration of w-6-polyunsaturated fatty acids with a simultaneous increase in the concentration of w-3 polyunsaturated fatty acids. The results can serve as a basis for comparative analysis development tools and strategies aimed at improving the nutritional characteristics of sheep’s milk cheese

Immobilisation of bifidobacteria in biodegradable food-grade microparticles

The present research features a natural polymer that can be used for immobilisation of bifidobacteria as well as a method of immobilisation. We described a modified method of microencapsulation of probiotics using sodi- um alginate. The experiment studied the effect of encapsulation on probiotic stability and involved an in vitro model of human digestive tract. The test sample of microencapsulated Bifi obacterium bifi um 791 showed a decrease in the activity from 3.0×107 to 2.2×105 CFU/ml in a mouse model with pH 1.2. By contrast, the control sample, unprotected by biodegradable polymer microcapsules, demonstrated a higher death rate of bifidobacteria: from 2.6×108 CFU/ml to 5.0×103 CFU/ml. The control sample demonstrated the same downward trend in in vitro gastrointestinal models with pH values of 4.5, 6.8, 7.2, and 5.8. Because the total plate count fell down to 4.0l g CFU/ml in acidity gradients, the titres of the initial microencapsulated biomass had to be increased up to > 109 CFU/ml. According to the results of scanning electron microscopy, the new type of microcapsules obtained by using a resistant starch had a closed sur- face. Prebiotics increased the resistance of bacteria to low pH and bile salts. Bifidobacteria encapsulated with natural biodegradable polymers proved to be well-tolerated and harmless for mice. The experiment revealed that biodegrad- able polymer microcapsules did not cause any chronic or acute toxicity when administered orally at 2×107 CFU per 1 gram of animal mass. The microcapsules demonstrated neither dermonecrotic properties nor any irritant effect on the ocular mucosa and, thus, can be used for food enforcement

Study of Fatty-acid Composition of Goat and Sheep Milk and Its Transformation in the Production of Yogurt

The information on the structure of fatty acids is crucial for the production and promotion of goat and sheep milk in the manufacture of dairy products. The fatty-acid profile of milk fat can affect the nutritional value and market value of dairy products. The purpose of the research is to study the properties of fatty-acid composition of goat and sheep milk and its transformation in the process of yogurt production. The study of fatty-acid composition was performed using the method of gas chromatography. The milk of goats of Zaanen breed and sheep of North Caucasian breed, as well as yogurt produced from a mixture of goat and sheep milk in a ratio of 1:1 have become the objects of the study. It was found that goat's milk contains 12% less saturated fatty acids than sheep's milk. Oleic, stearic and palmitic acids are the main fatty acids found in the fat phase of milk and yogurt production. Changes in the concentration of individual fatty acids during milk processing and in the period of yogurt storage were noted. As a result of maturation and seven-day storage, the amount of saturated fatty acids in yogurt increased by 5% compared to the original milk mixture. The content of polyunsaturated fatty acids in yogurt decreased by 19.27 %. The highest ratio value of hypocholesterolemic and hypercholesterolemic fatty acids was noted in goat milk. It is proved that goat milk is characterized by the most acceptable fatty acid composition in terms of healthy nutrition and prevention of atherosclerosis and thrombosis. A tendency to reduce the amount of monounsaturated and polyunsaturated fatty acids, with a simultaneous increase in the content of saturated fatty acids is noted in the process of yogurt production and storage. It was found that the production of yogurt with the use of goat's milk in the mixture allows reducing the values of atherogenicity and thrombogenicity indices. The results of the study provide an information basis for the production of qualitatively new fermented milk drinks with a fatty-acid profile favorable for human health

Zn\u3csup\u3e2+\u3c/sup\u3e-mediated Structure Formation and Compaction of The “Natively Unfolded” Human Prothymosin α

Human recombinant prothymosin α (ProTα) is known to have coil-like conformation at neutral pH; i.e., it belongs to the class of “natively unfolded” proteins. By means of circular dichroism, SAXS, and ANS fluorescence, we have investigated the effect of several divalent cations on the structure of this protein. Results of these studies are consistent with the conclusion that ProTα conformation is unaffected by large excess of Ca2+, Mg2+, Mn2+, Cu2+, and Ni2+. However, Zn2+ induces compaction and considerable rearrangement of the protein structure. This means that ProTα can specifically interact with Zn2+ (KD ∼ 10−3 M), and such interactions induce folding of the natively unfolded protein into a compact partially folded (premolten globule-like) conformation. It is possible that these structural changes may be important for the function of this protein