Processing Properties Of Milk Research Articles

АЛЛЕЛЬНЫЙ ПОЛИМОРФИЗМ ГЕНА КАППА-КАЗЕИНА (CSNЗ) У БЫКОВ-ПРОИЗВОДИТЕЛЕЙ ЧЕРНО-ПЁСТРОЙ ПОРОДЫ

The leading role in increasing dairy cow performance is played by seed bulls; 90-96% of the herd genetic progress depends on them. This is due to the fact that for this group of animals the genetic evaluation of the individuals used is reliably carried out and the worst andmoderate animals in terms of breeding qualities are most intensively culled from reproduction. Therefore, when pure-breeding and choosing seed bulls for the herd, the information on the genotypes of milk protein alleles, in particular the kappa-casein gene (CSN3), should be taken into account. The experimental studies were carried out in the livestock breeding operation of the AO “Plempredpriyatiye Barnaulskoye”. It has been found that the prevailing genotype in the Black Pied seed bulls is the CSNAA genotype; its frequency reaches 0.578; the alternative CSN3ВB genotype is found in single ani-mals. The allele A accounts for 0.756, and B -0.245. Among the Black Pied seed bulls, no statistically significant shift in genetic equilibrium was found for any of the three genotypes of kappa-casein gene locus. The studies of the polymorphism of the kappa-casein gene in the seed bulls taking into account their line belonging have revealed that only in the Vis Back Ideal line there is a BB genotype asso-ciated with the processing properties of milk, while it lacks in the bulls of the Montwick Chieftain and Reflection Sover-ing lines. The genotype CSN3AA prevails in the seed bulls of all lines; the highest frequency occurs in the Reflection Sovering line -0.625, and the lowest in the Vis Back Ideal line -0.542. The differences in the allele frequencies be-tween the lines, apparently, are associated with the peculi-arities of the origin of the seed bulls and the direction of the selective breeding work with the Black Pied cattle.

Is it possible to predict milk processing into butter using infrared spectroscopy?

Description of the subject. Given the current low price of milk, a lot of producers have decided to process their milk into products with a higher added-value, including butter. However, all milks are not suitable to be transformed into butter. It would thus be useful to be able to predict milk processing properties. Objectives. The aim of this paper was to study the ability of milk to be processed into butter using infrared spectrophotometry. Method. A normalized protocol for the production of butter was developed. Milk samples (n = 110) collected between 2013 and 2016 were analyzed by near and medium infrared spectrometry (315 spectra). Butter samples were also analyzed by visible-near infrared spectrometry (220 spectra). Composition of the products was subsequently assessed using validated prediction equations. Principal components analyses were performed to discriminate samples. Results. Butter properties seemed to be influenced by seasons and feedings. Water content and color parameters could be predicted on the basis of butter infrared spectra. Conclusions. It was possible to correlate butter characteristics with milk properties. However, it was not possible to predict butter characteristics on the basis of milk near infrared spectra. It could be interesting to try predictions from milk medium infrared spectra.

Genomic analyses for predicted milk fatty acid composition throughout lactation in North American Holstein cattle

Milk fat composition has important implications in the nutritional and processing properties of milk. Additionally, milk fat composition is associated with cow physiological and health status. The main objectives of this study were (1) to estimate genetic parameters for 5 milk fatty acid (FA) groups (i.e., short-chain, medium-chain, long-chain, saturated, and unsaturated) predicted from milk infrared spectra using a large data set; (2) to predict genomic breeding values using a longitudinal single-step genomic BLUP approach; and (3) to conduct a single-step GWAS aiming to identify genomic regions, candidate genes, and metabolic pathways associated with milk FA, and consequently, to understand the underlying biology of these traits. We used 629,769 test-day records of 201,465 first-parity Holstein cows from 6,105 herds. A total of 8,865 genotyped (Illumina BovineSNP50K BeadChip, Illumina, San Diego, CA) animals were considered for the genomic analyses. The average daily heritability ranged from 0.24 (unsaturated FA) to 0.47 (medium-chain and saturated FA). The reliability of the genomic breeding values ranged from 0.56 (long-chain fatty acid) to 0.74 (medium-chain fatty acid) when using the default τ and ω scaling parameters, whereas it ranged from 0.58 (long-chain fatty acid) to 0.73 (short-chain fatty acid) when using the optimal τ and ω values (i.e., τ = 1.5 and ω = 0.6), as defined in a previous study in the same population. Relevant chromosomal regions were identified in Bos taurus autosomes 5 and 14. The proportion of the variance explained by 20 adjacent single nucleotide polymorphisms ranged from 0.71% (saturated FA) to 15.12% (long-chain FA). Important candidate genes and pathways were also identified. In summary, our results contribute to a better understanding of the genetic architecture of predicted milk FA in dairy cattle and reinforce the relevance of using genomic information for genetic analyses of these traits.

Natural variations of citrate and calcium in milk and their effects on milk processing properties

Natural variations among milk constituents, and their relations to each other as well as to processing parameters, represent possibilities for differentiation of milk to produce high-quality natural products. In this study, we focused on natural variations in milk citrate and its interplay with calcium distribution in milk, in relation to processing properties. Milk samples from individual cows from farms varying in feeding and management practices were collected from April to June 2017 to maximize natural variations in citrate and calcium. Chemical composition, rennet coagulation properties, and ethanol stability were analyzed for all milk samples. We focused particularly on calcium distribution and citrate content and the correlation of these to other milk parameters. No significant change in citrate content was observed during the sampling period, which suggests that mechanisms other than feeding affect citrate levels in milk. Several significant correlations were found, including a positive correlation between complexed serum calcium and citrate, and a negative correlation between urea and ionic calcium. These are both of interest in relation to further processing, as with regard to the stability of UHT milk and in cheese making. Although the correlation between complexed serum calcium and citrate may be explained by their affinity, the underlying driver for the negative relationship between natural milk urea and ionic calcium needs to be clarified by further studies. Furthermore, milk from the different farms varied not only with regard to organic versus conventional farming systems; feeding practices between farms also play an important role in milk composition and functionality. However, none of the differences in milk composition between farms were found to decrease milk functionality and thus would probably not cause any processing problems.

Bioactive peptides from milk: animal determinants and their implications in human health.

Milk is an important protein source in human diets, providing around 32 g protein/l (for bovine milk, which constitutes some 85% of global consumption). The most abundant milk proteins are α-lactalbumin, β-lactoglobulin, αs-casein, β-casein, and κ-casein. Besides their nutritional value, milk proteins play a crucial role in the processing properties of milk, such as solubility, water bonding, heat stability, renneting and foaming, among others. In addition, and most importantly for this review, these proteins are the main source of bioactive components in milk. Due to the wide range of proposed beneficial effects on human health, milk proteins are considered as potential ingredients for the production of health-promoting functional foods. However, most of the evidence for bioactive effects comes from in vitro studies, and there is a need for further research to fully evaluate the true potential of milk-derived bioactive factors. Animal genetics and animal nutrition play an important role in the relative proportions of milk proteins and could be used to manipulate the concentration of specific bioactive peptides in milk from ruminants. Unfortunately, only a few studies in the literature have focused on changes in milk bioactive peptides associated to animal genetics and animal nutrition. The knowledge described in the present review may set the basis for further research and for the development of new dairy products with healthy and beneficial properties for humans.

Genetic diversity of milk protein beta-lactoglobulin and association with production traits genomic values among Holstein cattle

The aim of the study was to evaluate the prevalence of beta-lactoglobulin genotypes in Lithuanian Holstein dairy cattle population and to identify possible synergies between the different genotypes of beta-lactoglobulin and genomically predicted values for milk production traits. DNA samples were collected from Holstein cattle (147) and bovine beta-lactoglobulin gene polymorphism study was performed by PCR-RFLP method. A allele was identified with frequency 0.456, B allele, which can be used to carry out selection to improve milk processing properties, was found with 0.544 frequency. Three genotypes, viz. AA, AB, BB at different frequencies were identified. The biggest influence on the milk processing properties having BB genotype was found in 27.3% of the cows. Beta-lactoglobulin AA genotype cows had higher average genomic values for milk yield, while BB genotype cows had higher average genomic values for milk protein percentage, the differences have found statistically significant. Dispersion analysis showed that beta-lactoglobulin genotype influences 8.4% of milk amount genetic variation, 1.2% of milk protein amount genetic variation and 20.6% of milk protein percent genetic variation. Lithuanian Holstein cows population had higher average genomic prediction values for milk yield, milk protein amount and milk percentage than average genomic values of Igenity reference animal group. The existence of the most important genotype BB of beta-lactoglobulin for milk manufacturing properties, in studied population increases the possibility of selecting cows according to milk protein polymorphism, and could be economically important selection criteria for dairy herds designated for industrial milk production.

Ultrasound effects based on simulation of milk processing properties

Efficient reconstitution followed by fermentation of nonfat (skimmed) dry milk is one of the most important aspects in manufacturing of various dairy products. As a first stage, dry milk is normally being reconstituted using conventional approaches such as heating and stirring the mixture. Nevertheless, we demonstrated, that low-frequency (22 ± 1.65 kHz) ultrasound can be used as an alternative to the traditional methods of milk recovery. Low-frequency ultrasound was applied during pre-fermentation stage to improve the dispersity of the resulting milk product and to create good conditions for a post-ultrasound bacterial fermentation of milk. The applied ultrasound power was set in the range of 60–120 W/L. For the fermentation process we used: kefir fungi, fermenter of direct inoculation for yogurt LYOBAC YOYO and mixed culture for kefir LAT LC K. The effectiveness of ultrasound treatment was evaluated based on the accumulation of exopolysaccharides (EPS), vitamin C content, as well as antioxidant activity of the resulting milk product. The effect of ultrasound on microflora and the role of the specific types of bacteria such as Lactobacillus on the accumulation of biologically active compounds in the fermented milk products was studied with use of electron microscopy and MALDI – to FMS method. Overall, our results showed that reconstitution of dry milk with use of ultrasound improves further accumulation of biologically active compounds and rises the nutritional quality of the fermented product.

Molecular Characterization of Genetic Variability among Sudanese Baggara Cattle within Kappa Casein Csn3 Gene (Exon V)

The present work was conducted to detect possible genetic variants of kappa casein (CSN3) gene in Western Baggara cattle in Sudan. This gene is associated with higher fat, protein, and has a significant influence on milk processing properties in comparison to other casein variants. 70 blood samples were collected from Western Baggara cattle in three areas (Hai Elgabal, Bulbul and Umdamm). Genomic DNA was extracted from the whole blood using guanidine chloroform method. A 495 bp fragment containing exon V of kappa casein gene was amplified by PCR using specific set of primers. The amplified PCR product was digested by Hinf1; the bands were visualized under UV-light to observe the polymorphic locus by the size change of DNA fragments. The results revealed that the restriction analysis produced two fragments of 424 and 71 bp indicating the presence of kappa casein BB genotype (monomorphic) in all population. The present study is the first report on kappa casein genotype of Baggara cattle in South Darfur State, Sudan, which elucidated uniform and homozygous population for kappa casein B allele.

The effect of crude protein in the diet on the quantity and composition of milk in Alpine goats

The excess of protein and lack of energy in the diet of goats cause an excess of nitrogen compounds in the rumen with the release of ammonia and the increase of urea concentration in blood and milk, which adversely affects: production and processing properties of milk, environmental pollution and reproductive performance. The aim of the present study was to determine the effect of short-term (30 days) changes of meals in the view of different content of crude protein (CP) to: daily milk yield (DMY), the concentration of urea (U) and the ratio between fat and protein (F/P) in milk. Preliminary research was conducted on 72 Alpine goats, grouped into three groups (I, II, III), with 24 randomly selected goats. From kidding to weaning, goats were fed with the same meal (11 % CP), which was followed by period of short-term feeding with different amounts of CP in the meal (I -14 % low proportion, II - 16 % optimal proportion, III - 18 % high proportion). The increase of CP in portion for 4 %, 4 % and 6 % resulted in an increase of the DMY for: 1.29 L, 1.48 L and 1.91 L, and also the concentration of urea for 16, 26 and 30 mg/100 mL. The ratio of F/P decreased in I, II, and III group from 1.55 to 1.24; from 1.53 to 1.18 and from 1.39 to 1.12. Optimizing nutrition in terms of a more rational protein intake as the most expensive components of a meal, balance of the energy and protein, as well as defining the limit value of urea concentration in milk are a prerequisite for intensive production of goat’s milk.

Polymorphisms in lipogenic genes and milk fatty acid composition in Holstein dairy cattle

Changing bovine milk fatty acid (FA) composition through selection can decrease saturated FA (SFA) consumption, improve human health and provide a means for manipulating processing properties of milk. Our study determined associations between milk FA composition and genes from triacylglycerol (TAG) biosynthesis pathway. The GC dinucleotide allele of diacylglycerol O-acyltransferase 1:g.10433-10434AA >GC was associated with lower palmitic acid (16:0) concentration but higher oleic (18:1 cis-9), linoleic (18:2 cis-9, cis-12) acid concentrations, and elongation index. Accordingly, the GC dinucleotide allele was associated with lower milk fat percentage and SFA concentrations but higher monounsaturated FA and polyunsaturated FA (PUFA) concentrations. The glycerol-3-phosphate acyltransferase, mitochondrial haplotypes were associated with higher myristoleic acid (14:1 cis-9) concentration and C14 desaturation index. The 1-acylglycerol-3-phosphate acyltransferase 1 haplotypes were associated with higher PUFA and linoleic acid concentrations. The results of this study provide information for developing genetic tools to modify milk FA composition in dairy cattle.

Milk protein polymorphism in a Holstein–Friesian nucleus exploited in the North-East of Romania

Since the discovering of the first genetic polymorphism at beta-lactoglobulin locus (β-LG) by Aschaffenburg et.al. [2], the researchers worldwide became interested in genetic polymorphisms of major milk proteins. As a fact, until now, numerous studies were carried in order to show the influence of the genetic variants of milk proteins on milk quality and quantity. Nowadays at least 39 genetics variants (alleles) are known for the six major milk proteins . These alleles occur because of the substitutions or deletions of the peptidic chain aminoacids [12]. Because of some certain genetic variants impact on the quantity, quality and processing properties of milk, we can discuss about an economic importance. Knowing the genetics polymorphisms helps in practice, because we can select through genetic tests, those individuals who might have important alleles. This way we can accelerate the improvement process of milk production [3; 11]. Major proteins polymorphisms are related to human nutrition in many ways: hypoallergenic properties of some types of milk; releasing the peptides with biological functions from milk proteins and other. [9]. The information gathered in this study may be used for milk improvement, specialy of the casein content. For example, the cheese production capacity is associated with a higher content of protein, casein and fats [7]. More than that these information can be used in order to produce a healthier milk with no negative effects on human health [5].

Qualitative characteristics and processing properties of milk from various cow breeds

Kappa-casein gene (CSN3) polymorphism has been established in cows of the Belarus Black Pied breed and Belarus Red breed group. The frequency of genotypes and alleles across gene CSN3 has been calculated. More cheese and curd can be made from milk of cows of the Belarus Red breed group with genotype CSN3 BB than from milk of animals with genotype CSN3 AB and CSN3 AA.

Physical and Processing Properties of Milk, Butter, and Cheddar Cheese from Cows Fed Supplemental Fish Meal

Physical, chemical, sensory and processing properties of milk produced by feeding a rumen-undegradable fish meal protein supplement to Holstein cows were investigated. The supplement contained (as fed basis) 25% soft-white wheat, 60% herring meal, and 15% feather meal. The total fat level in the milk decreased to 2.43%. For both pasteurized and ultra-high temperature processed drinking milk, no difference was found between fish meal (FM) milk and control milk in terms of color, flavor and flavor stability; in particular, no oxidized flavor was observed. Cheddar cheese made from FM milk ripened faster after 3 mo of ripening and developed a more desirable texture and stronger Cheddar flavor. The yield efficiencies for FM and control cheese, 94.4 (±2.44 SE) and 96.4 (±2.26 SE), respectively, were not different. Relative to controls, average fat globule size was smaller in FM milk and churning time of FM cream was longer. FM butter had softer texture and better cold spreadability, and butter oils from FM enriched milk had lower dropping points compared to control butter oil (average 32.89 versus 34.06°C). These differences in physical properties of butter fat were greater than expected considering that iodine values were not different. This study demonstrates the feasibility of producing high quality products from milk naturally supplemented with FM, but the results also show that dietary changes affect processing properties.

Factors affecting the clotting properties of sheep milk

AbstractA Formagraph was used to test the effects of some of the exogenous factors that can affect the processing properties of milk (pH, soluble calcium, rennet concentration, coagulation temperature), and two of the endogenous factors (protein and fat concentration), on the comparative clotting properties of sheep and cows' milk, namely renneting time (r), rate of firming (k20) and curd consistency (A30). A lower pH decreased r and k20 and increased A30 in both sheep and cows' milk. The addition of calcium chloride did not affect the clotting properties of sheep milk, but in cows' milk it decreased r and k20 and increased A30. Increasing the concentration of rennet decreased r and k20 and increased A30 for both sheep and cows' milk. Increasing the coagulation temperature from 30 to 38 °C decreased r for both sheep and cows' milk, but it decreased k20 and increased A30 only in cows' milk. Increasing the protein concentration decreased r in both sheep and cows' milk; it did not affect k20 of sheep milk, but it decreased that of cows' milk and increased A30 in both milks. Increasing the fat concentration had little effect on r and k20 in either sheep cows' milk, but it decreased A30 in both milks. In general, sheep milk had faster renneting times and rates of firming and greater curd consistency than cows' milk, and its clotting properties tended to be less affected by changes in the clotting conditions.© 2002 Society of Chemical Industry

Options for genetic improvement of milk composition

Genetic improvement is constrained by the long-term and cumulate nature of genetic improvement, by the economic rewards for making genetic change and by the variances and covariances among traits of interest. Genetic change is cumulate, so that small annual changes make substantial differences over time. This cumulate nature of genetic improvement dictates the importance of identifying long-term goals driven by robust economic signals and then adhering to them. The economic rewards for genetic improvement will ultimately determine the uptake and therefore the success of any breeding program. In developed countries the value of milk can be divided between the weight of water, fat and protein produced. Water generally has a negative value due the cost of handling, removal and disposal. Fat and protein have varying values depending on the market, but both will always have underlying positive values. Genetic variances and covariances among the aggregate composition traits, water, fat and protein, are such that simultaneous increase in the yield of all three is considerably easier than improvement of just one, or improvement of one while decreasing others. Selection for simultaneous increase of fat and protein percentage will also be successful, but at the price of not increasing fat and protein yield nearly as rapidly as when selecting directly on yield traits. In virtually all developed countries, the optimum selection goal will be for some combination of increased fat and protein yield that may lead to a gradual increase in the protein to fat ratio. Genetic polymorphisms in several protein genes have been associated with yield and with milk processing properties, but are unlikely to play more than a minor role in overall selection. There is some evidence of genetic variation in milk fat composition, but the level of variation and economic incentives for change mean that selection for milk fat composition is not worthwhile. Thus, with the exception of very slow changes in the water to fat to protein yield ratio, genetic improvement does not seem a particularly suitable route for altering milk composition.

Non-nutritional (novel) techniques for manipulation of milk composition

AbstractThis review considers the control of milk composition by endocrine factors and local mechanisms operating within the udder, and the impact of management systems and the environment on these control systems. Much less is known about control of milk composition than yield, although one can propose that prolactin is more concerned with control of lactose and protein secretion whilst growth hormone has a bigger role to play in fat secretion. Molecular biological approaches have the potential to increase understanding and, in the distant but foreseeable future, to manipulate milk composition on a commercial scale. The feedback inhibitor of lactation (FIL), which is responsible for local control of milk yield, has equal effects on lactose, fat and protein secretion, so changes in milking frequency do not alter gross milk composition. During the course of lactation the processing properties of milk gradually deteriorate as a consequence of proteolytic degradation of caseins, but new research shows that this can largely be prevented by milking thrice–daily. This has significant implications for future milking strategies such as robotic milking and extended lactation.

Production and metabolic aspects of nonprotein nitrogen incorporation in lactation rations of dairy goats

Two lactation trials were conducted to evaluate the effects of dietary urea on milk production and metabolic criteria in dairy goats. In Experiment 1, 18 primiparous Alpine does (average BW 42kg) were fed one of three diets (65% TDN): NPC1, negative protein control (9.5% CP); PPC1, positive protein control (14% CP); and NPND, nonprotein N diet (14% CP, urea contributed 33% of the total dietary N). The lactation trial consisted of a 3 week adaptation and a 5 week collection period. Mean ADG, DM intake, milk yield, milk fat, and milk N were not affected by diet ( P > 0.10); however, milk noncasein N ( P < 0.02) and serum-derived protein N ( P < 0.05) were greater in the does fed the NPND diet compared with the does fed the NPC1 diet. Ruminal fluid ammonia N ( P < 0.01) and plasma urea N ( P < 0.001) were increased by dietary N level and NPN incorporation, and ruminal acetate:propionate molar ratio was lower ( P < 0.02) in does fed NPND compared with does fed PPC1. In Experiment 2, 20 multiparous Alpine does (average BW 55 kg) were fed one of four diets (65% TDN): NPC2, negative protein control (12.5% CP); PPC2, positive protein control (17% CP); LNPN, low nonprotein N (17% CP, urea contributed 25% of the total dietary N); and HNPN, high nonprotein N (16% CP, urea contributed 50% of the total dietary N). The lactation trial lasted 10 weeks following a 3 week adaptation period. Mean ADG, DM intake, milk yield, and milk fat were not affected by dietary treatment ( P > 0.10). Total milk N was affected ( P < 0.002) by diet. The NPN fraction was lowest ( P < 0.04), and the true protein N ( P < 0.005) and casein N ( P < 0.001) fractions highest in milk from does fed NPC2 compared with does fed PPC2. In addition, milk true protein N and casein N fractions were lowest in does fed the HNPN diet ( P < 0.005). Increasing dietary N levels and incorporation of NPN resulted in elevated ruminal fluid pH ( P < 0.10), ammonia N ( P < 0.02), and free, nonionized ammonia N ( P < 0.03). Ruminal fluid acetate:propionate molar ratio was lowest ( P < 0.001), and plasma ammonia N ( P < 0.04) and urea N ( P < 0.01) were elevated in does fed the HNPN diet. Plasma glucose, insulin, glucagon, and cortisol were not affected ( P > 0.10) by diet in either experiment. Incorporation of NPN in goat lactation diets can sustain milk yield during mid-lactation without the development of clinical hyperammonemia; however, milk N fractions, and hence, the milk processing properties may be affected at the higher levels of NPN incorporation.

Milk composition and lactation of beta-casein-deficient mice.

beta-Casein is a major protein component of milk and, in conjunction with the other caseins, it is assembled into micelles. The casein micelles determine many of the physical characteristics of milk, which are important for stability during storage and for milk-processing properties. There is evidence that suggests that beta-casein may also possess other, nonnutritional functions. To address the function of beta-casein, the mouse beta-casein gene was disrupted by gene targeting in embryonic stem cells. Homozygous beta-casein mutant mice are viable and fertile; females can lactate and successfully rear young. beta-Casein was expressed at a reduced level in heterozygotes and was completely absent from the milk of homozygous mutant mice. Despite the deficiency of beta-casein, casein micelles were assembled in heterozygous and homozygous mutants, albeit with reduced diameters. The absence of beta-casein expression was reflected in a reduced total protein concentration in milk, although this was partially compensated for by an increased concentration of other proteins. The growth of pups feeding on the milk of homozygous mutants was reduced relative to those feeding on the milk of wild-type mice. Various genetic manipulations of caseins have been proposed for the qualitative improvement of cow's milk composition. The results presented here demonstrate that beta-casein has no essential function and that the casein micelle is remarkably tolerant of changes in composition.

Microbiological Problems in Dairy Foods in the 1980s

Microorganisms are important to the dairy industry. Some bacteria and molds are used to manufacture dairy products while others cause spoilage or are potential health hazards. Many of the microbiological problems challenging the dairy industry in the 1980s will not be new. Psychrotrophic bacteria will continue to be a problem, but more effort will be directed toward elucidating their effect on processing properties of milk and the significance of enzymes produced by them. Heat-stable enzymes that cause quality problems will become more important as efforts to achieve a longer shelf-life for products are realized. Acceptance of reverse osmosis and ultrafiltration for concentrating milk and whey might increase if energy costs continue to rise or if economic advantages such as increased cheese yield can be accomplished. Microbiological problems associated with the product processed, processing parameters and sanitary design of this equipment will emerge if greater use of the technology is implemented. Microbial production of toxic metabolites and biologically active chemicals such as mycotoxins and amines will emerge as primary factors in the public health area as the research in food toxicology expand.