Genetic factors affecting the composition and quality of cow’s milk

This chapter reviews the genetic factors affecting the composition and quality of cow's milk. It starts by discussing how different breeds of cattle can affect the composition of milk. The chapter then goes on to examine milk proteins, genetic variants and post-translational modifications. It then discusses milk coagulation and other functional properties, before highlighting the genetic influence of fatty acids on minor milk components. The chapter also discusses using mid-infrared spectroscopy for genetic parameter estimation, before concluding with a section on the possibilities for genetic improvement in relation to dairy milk.

First Insight into the Variation of the Milk Serum Proteome within and between Individual Cows

Milk contains all nutrients needed for development of calves. One important group of components responsible for this are the milk proteins. Variation due to feed or animal health, has been studied for the most abundant milk proteins. The aim of this study was to determine the variation between and within cows for their milk serum proteome. Sample Set 1 was collected from Holstein Friesian (HF) cows between November 2011 and March 2012 and prepared using filter aided sample preparation (FASP) followed by LC-MS/MS for protein identification and quantification. The results showed that the milk serum proteome was very constant in mid lactation (four cows at five time points, p > 0.05) between 3 and 6 months in lactation. Sample Set 2 was collected from HF cows in Dec 2012 and analyzed using FASP and dimethyl labeling followed by LC-MS/MS. Significant variation in the milk serum proteome (p < 0.05) between 17 individual cows was found in Sample Set 2. The most variable proteins were immune-related proteins, which may reflect the health status of the individual cow. On the other hand, proteins related to nutrient synthesis and transport were relatively constant, indicating the importance of milk in providing a stable supply of nutrients to the neonate. In conclusion, the milk serum proteome was stable over mid lactation, but differed significantly between individuals, especially in immune-related proteins.

Functional Properties and Metabolic Profile of National Fermented Products of Russia and South Africa

. Both Russia and South Africa have a long-standing history of fermented milk product consumption. Along with the products widely distributed around the world, such as yoghurts, in each of these countries there are a number of national products. An example of a widely demanded fermented milk product in Russia is Kefir.This productis used not only as a food source in the diet of children and adults, but also in medical institutions, since ithasa positive effect onhuman health when consumed regularly. South Africa is characterized by the consumption of products such as Amasi,which is produced commercially. Its consumption has also been shown to have beneficial effects on the digestive system. In this research, the metabolic profiles(fatty acid composition and volatile compounds) of these fermented milk products were analyzed and these showed significant differences. The results indicated that this metabolite composition reflected the different production protocols and microbial complexity of these dairy products. The functional properties of the studied drinks were also considered.The average content of L-leucine equivalents in Amasi was slightly higher (6.5-8.9mMol×L −1) than in Kefir (4.9-6.7mMol×L −1). Antioxidant and antihypertensive activity of the fermented products correlated with the depth of hydrolysis of the milk proteins. Amasishowed higher antioxidant and antihypertensive activities (600- 796µМolТE/ml and 1.3-1.5mg/ml, respectively) than Kefir (246-574µМolТE/ml and 2.0-4.3mg/ml, respectively). Keywords: fermented products, Kefir, Amasi,metabolic profile, antioxidant potential, antihypertensive properties

Probiotic Potential and Functional Properties of Lactobacillus Reuteri, Lactobacillus Rhamnosus and Lactobacillus Helveticus: A Comparative Study

This study was conducted to evaluate and comparethe probiotic propertiesofLactobacillus helveticusNK1, Lactobacillus rhamnosusF and Lactobacillus reuteriLR1lactobacilli strains.Changes in pH, cell growth, proteolytic activity, antioxidantactivity, and angiotensin-converting enzyme(ACE)inhibitoryactivity were monitored during fermentation ofreconstituted skim milk (RSM) by pure cultures of lactobacilli.Among the tested strains, L. helveticusNK1 showed the highest proteolytic, ACE inhibitoryand antioxidantactivitiesduring milk fermentation,followed by L. rhamnosus F and L. reuteriLR1.The promising capability of all of the lactobacilli strains to release bioactivepeptides from the milk proteins was demonstrated. Keywords: Lactobacillus, probiotic, milk fermentation, bioactive peptides

Camel milk modulates α-lactalbumin induced changes in the gut microbiota in a murine model of cow’s milk allergy

Camel milk has been noted to have medicinal properties treating allergies, diarrhea, microbial infection and Crohn's disease.The aim of this study is to identify and characterize the intestinal microbiota of BALB/c mice sensitized to α-lactalbumin (α-la) and fed with camel milk. For this, 30 females BALB/c mice aged between 4 and 6 weeks were divided into two groups. The first one designated as control group did not receive any treatment (n=10). The second group (n=20) was immunized intraperitoneally with α-la. On day 35 of sensitization protocol, mice of the second group were divided into two subgroups of 10 mice each. Animals of the first subgroup were sacrificed, whereas, mice of the second subgroup were fed camel milk for one week. In order to analyze the effect of camel milk on α-La-sensitized mice, two studies were carried out: a histological analysis of the jejunal tissues and microbiolo-gical study in the intestine and faeces of mice of different groups. Our results showed that drinking camel milk significantly reduced the alteration of in-testinal epithelium induced by α-la immunization as demonstrated by a signi-ficant increase of villus height (p<0.05). The microbiological results showed a very significant increase in enterobacteria and anaerobic bacteria (1 to 2 log ufc/g) in bacterial flora of mice immunized to α-la. However there was no significant difference in the level of enterobacteriaceae and anaerobic bacte-ria in the faeces of α-la-immunized mice treated with camel milk. In conclu-sion, Camel milk reduced the microscopic lesions caused by α-lasensitization and play an antibacterial role againstpathogenic bacteria in the intestinal mucosa of mice immunized to cow’s milk proteins especially α-la.

Features of the formation of specific Igg4 antibodies to milk proteins in healthy young children living in different megalopolises of the Russian Federation

Objective: Study specific Igg4 antibodies to milk proteins indexes in healthy babies living in different Russian megalopolises.Methods: The complex research of the specific Igg4 antibodies to milk proteins during cohort study of 259 healthy babies of the first year of life. Children lived in five Russian cities: 60 children in Moscow, 50 newborns – in Saint Petersburg, 55 children came from Kazan, 43 children lived in Khabarovsk and 51 – in Vladivostok. Non-competitive enzyme-linked immunosorbent assay was used to quantify specific Igg4 antibodies to cow milk proteins (CMP), beta-lactoglobulin (β-LG), alpha-lactalbumin (α-LA), casein and goat's milk protein (GM) in coprofiltratesResults: The highest frequency of the high Igg4 was discovered to CMP and goats’ milk was observed among children from Saint Petersburg during comparative assessment of the frequency of defining Igg4 to milk proteins in healthy newborns aged 2.5 months living in Moscow and Saint-Petersburg. The highest frequency of Igg4 increased rates to milk proteins among newborns from Kazan, Khabarovsk and Vladivostok was diagnosed during first three months of life on breastfeeding without any clinical symptoms of food intolerance. With age decrease of the frequency of specific Igg4 to milk proteins were observed among all babies from above-mentioned cities. By 8 month of life it made isolated cases.Conclusions: High frequency of increased Igg4 to milk proteins among 2 months old babies on breastfeeding was observed in the cities of Central and Far Eastern districts of Russian Federation. In this regard it can be supposed that Igg4s were got from mothers in the prenatal period and after birth through breastfeed. The presence of high frequency of the increased indexes of specific Igg4 to milk proteins probably was related to mothers’ nutrition habits during pregnancy and lactation periods.

Effects of Microwaves, Ultrasonication, and Thermosonication on the Secondary Structure and Digestibility of Bovine Milk Protein

Cow’s milk is considered an excellent protein source. However, the digestibility of milk proteins needs to be improved. This study aimed to evaluate the relationship between the functional properties of milk proteins and their structure upon microwave, ultrasound, and thermosonication treatments. The protein content, digestibility, and secondary-structure changes of milk proteins were determined. The results demonstrated that almost 35% of the proteins in the untreated samples had a α-helix structure and approximately 29% a β-sheet and turns structure. Regarding the untreated samples, the three treatments increased the α-helices and correspondingly decreased the β-sheets and turns. Moreover, the highest milk protein digestibility was observed for the ultrasound-treated samples (90.20–94.41%), followed by the microwave-treated samples (72.56–93.4%), whereas thermosonication resulted in a lower digestibility (68.76–78.81%). The milk protein content was reduced as the microwave processing time and the temperature increased. The final milk protein available in the sample was lower when microwave processing was conducted at 75 °C and 90 °C compared to 60 °C, whereas the ultrasound treatment significantly improved the protein content, and no particular trend was observed for the thermosonicated samples. Thus, ultrasound processing shows a potential application in improving the protein quality of cow’s milk.

Analysis of trypsin activity at β-casein layers formed on hydrophobic surfaces using a multiharmonic acoustic method

Proteolysis of milk proteins, such as caseins, caused by milk proteases, can change the organoleptic and nutritional characteristics of milk, and therefore it is essential to monitor this enzymatic activity....