Cheese Yield Research Articles

Productive traits of daughters of sires of Holstein breed depending on the country of origin and genotype according to gene CSN3

Numerous studies have proven the effect of the allele B of the kappa casein gene (CSN3) on protein milk content, because the protein controlled by this allele has a number of distinctive features: difference in micelle size, higher protein content, greater stability when heated and frozen, better properties for cheese making (shorter coagulation time, coagulate of a denser consistency and a higher cheese yield by 5–10 %). The purpose of the research was to study the frequency of occurrence of alleles and genotypes of the kappa casein gene (CSN3) in sires of Holstein breed, depending on the country of origin, and to trace the infl uence of the identifi ed genotypes on the productive traits of the daughters of sires (milk yield, fat and protein content in milk). It was revealed that the highest frequency of occurrence of the desired allele B kappa-casein was found in sires of Dutch and Canadian breeding 33,3 and 34,7 %, respectively. The highest frequency of occurrence of homozygous genotype CSN3 BB was found in Dutch–bred sires – 22,2 %. The frequency of occurrence of the heterozygous CSN3 AB genotype was higher than others in Canadian–bred sires – 36,1 %. The best milk yield was characterized by the daughters of Canadian and Dutch-bred sires with CSN3 AA genotype, among the daughters of Germanbred sires it was CSN3 AB. The highest amount of fat in milk of daughters of sires of Dutch origin was found in cows with the sire’s genotype AB, in daughters of sires of German and Canadian breeding itwas AA, but the indicators practically did not differ from those of daughters of sires with the genotype AB. The highest protein content in milk was found in the daughters of sires of diff erent origins with the allele B of the kappa-casein gene.

Efficiency of Manchega Sheep Milk Intended for Cheesemaking and Determination of Factors Causing Inefficiency.

Understanding the factors that determine and regulate cheese yield would allow, through deterministic parametric efficiency models, the determination of the most appropriate milk characteristics for the industry, and the estimation of a technological value for these characteristics. The present study aims to evaluate coagulation performance of Manchega sheep milk intended for cheesemaking and explores two models to determine milk technological efficiency. For this purpose, 1200 Manchega sheep milk samples were collected, and analyses were performed for composition, milk coagulation properties (MCP), somatic cell count (SCC), and milk color values. A first model was built based on curd yield (CE) and a second one based on dry curd yield (DCE). GLM and MANCOVA analyses were used to identify the factors that determine curd yield efficiency, which mainly depended on pH, casein, and lactose content and, to a lesser extent, on the speed of coagulation and curd firmness. When comparing both models, differences were linked to the water retention capacity of the curd. Based on this, the DCE model was considered much more accurate for prediction of coagulation efficiency in a wider variety of cheeses, as it does not seem to be affected by moisture loss.

Bovine beta casein polymorphism and environmental sustainability of cheese production: The case of Grana Padano PDO and mozzarella cheese

Several genetic variants of β-casein have been identified but A1 and A2 are the most common. Bovine β-casein variants may play an important role on cheese yield and quality, besides milk production and composition, and, thereby, affect environmental sustainability of cheese production processes. The aim of the study was to investigate the possible effect on environmental sustainability of cheese production, related to bovine β-casein polymorphism. A Life Cycle Assessment (LCA) was performed, considering Grana Padano PDO and mozzarella cheese, made with either A1A1, A1A2 or A2A2 β-casein milk and using economic and dry matter allocation methods for cheese and co-products. Additionally to characterization, normalization and weighting (endpoints method), were also performed. Results on the environmental impact of 1 kg of packaged cheese showed that, among the β-casein genetic variants, A1A1 seemed to be the most impactful, only due to the lower individual daily milk production of cows belonging to A1A1 group, compared to the cows belonging to A1A2 and A2A2 groups, i.e. 29.6, 37.1 and 34.6 kg of fat and protein corrected milk (FPCM) day cow −1 , respectively. Allocation method strongly affected the impacts per kg of cheese product and, consequently, of co-products. The normalization allowed to understand the relative importance of different impact categories and the result obtained indicated that the notable impact categories of the cheese industry were natural land transformation, aquatic eutrophication and terrestrial acidification. Results of the weighting highlighted that greater damage was given to the ecosystem quality, followed by human health and, finally, resource scarcity. Overall, biggest differences were detected for the two cheeses, rather than for the β-casein genetic variants and the differences in environmental sustainability of cheese made with A1A1, A1A2 and A2A2 milk were mainly due to the different cow milk production, rather than cheese yield. Therefore considering only the technological properties useful for cheese making the selection of milk with A2A2 β-casein may be not so convenient. Normalization and weighting results allow to identify the most impactful categories and so can help decision-makers to determine where to prioritize efforts aimed at reducing cheese environmental impact. • Effect of β-casein polymorphism on environmental impact of cheese was investigated. • LCA of Grana Padano PDO and mozzarella made with different β-casein milk was performed. • A1A1 cows produced slightly lower amounts of milk then A1A2 and A2A2 cows. • Natural land transformation was the most notably affected of the studied categories. • The greatest damage related to cheese production was given to the ecosystem quality.

The influence of goat crossbreeding (Arbia and Saanen) on the cheese yield in Algeria, Djelfa: a preliminary study

Goat's milk is an excellent source of nutrients because its composition is the closest to that of human milk. This work was concerned with the study of the influence of crosses between local (Arbia) and imported (Saanen) goat breeds raised in the Djelfa region on the yield of fresh cheese made from the milk of two goats. The cheese was made enzymatically using two enzymes of animal origin represented by the coagulating extract of the kaolin layer of chickens as well as bovine rennet, which were applied to goat milk. The obtained results showed that the cross goats cheeses presented better results compared to those of Arbia goats, where we noted cheese yields of 19.52 and 15.41, respectively, for the cheeses of cross goats and Arbia goats coagulated by the layer extract of Kaolin; likewise, the use of rennet confirmed a superiority of the cheese yield of around 17.62 for the product of crossbred goats against 14.45 characterizing that of Arbia goats.

Physicochemical, colour, textural, rheological and sensory properties of goatmilk mozzarella cheeses as affected for acidulants

The present study aimed at investigating the effectof four acidulants, viz., acetic acid (CAA), citric acid (CCA),hydrochloric acid (CHA) and lactic acid (CLA) on quality andacceptability of goat milk mozzarella cheese. Four differenttreatments were prepared using 25% (w/v) of acidulants and their physicochemical, functional, colour, textural, sensory and rheological properties were evaluated. No significant difference in cheese yield, pH, protein and fat were observed among treatments. However, titratable acidity for CCA was significantly higher (p<0.05) than for other treatments. Moisture and ash contents in CAA were significantly higher (p<0.05) than in CLAand CHA. Cheese CAA had significantly lower (p<0.05)meltability than the other treatments. The fat leakage for treatmentCCA was significantly higher (p<0.05) as compared to othercheeses. The Hunter colour redness (a*) value for CAA was significantly higher (p<0.05) compared to the other treatments. The yellowness (b*) value of treatment CAA was significantly higher (p<0.05) than the treatment CLA. The hardness and chewiness values for the treatments CAA and CHA were significantly higher (p<0.05) compared to the other two treatments. Cohesiveness and gumminess values were the highest for the treatment CAA, while these were the lowest for the treatment CLA. The evaluation of frequency and temperature sweeps of cheese samples revealed that the storage modulus(G’) and loss modulus (G”) for the treatment CHA was the highest, while the treatment CLA had the lowest values. The sensory characteristics of the cheeses from different treatments were statistically similar (p>0.05) except colour and appearance score, which was the highest for CCA. It can be concluded that though the type of acidulants had significant effects on various quality parameters of goat milk mozzarella cheese, their overallacceptability remained unaffected.

The influence of complex genotypes in the PRL and β-LG genes in Lacon sheep breed on cheese producing

For the first time, an analysis of the distribution of allele variants in the PRL and β-LG genes was conducted on the Russian population of Lakon sheep. The research established the influence of polymorphism in the studied genes on the quantitative and qualitative characteristics of Adyghe cheese. The analysis of data on 248 Lakon sheep showed a positive correlation between β-LGBB and PRLBB – with protein content in milk and better technological qualities for cheese production. The highest fat content in milk was observed in sheep with the β-LGBB genotype (7.14%). The cheese curd from milk of all genotypes was characterized by optimal density and good elasticity. The yield of Adyghe cheese obtained from milk of animals with the genotype PRLBBβ-LGBB was higher compared to the same parameter from milk of sheep with the genotypes PRLAAβ-LGAA, PRLBBβ-LGAA, PRLAAβ-LGBB by 5.5, 4.5, and 3.0%, respectively, and it also had a higher fat content by 3.04, 2.90, and 1.10%, respectively. The practical significance of the obtained data lies in the prospect of selecting carriers of desirable alleles of the PRL and β-LG genes for targeted selection of parental pairs and obtaining a larger number of offspring with homozygous genotypes. Targeted selection will provide a higher proportion of sheep in the herd with better quantitative and qualitative indicators of milk productivity for with better parameters for cheese production. The work was carried out by order of the Ministry of Agriculture of the Russian Federation No. 082-03-2023-213 dated March 07, 2023.

Milk metagenomics and cheese-making properties as affected by indoor farming and summer highland grazing.

The study of the complex relationships between milk metagenomics and milk composition and cheese-making efficiency as affected by indoor farming and summer highland grazing was the aim of the present work. The experimental design considered monthly sampling (over 5 mo) of the milk produced by 12 Brown Swiss cows divided into 2 groups: the first remained on a lowland indoor farm from June to October, and the second was moved to highland pastures in July and then returned to the lowland farm in September. The resulting 60 milk samples (2 kg each) were used to analyze milk composition, milk coagulation, curd firming, and syneresis processes, and to make individual model cheeses to measure cheese yields and nutrient recoveries in the cheese. After DNA extraction and Illumina Miseq sequencing, milk microbiota amplicons were also processed by means of an open-source pipeline called Quantitative Insights Into Microbial Ecology (Qiime2, version 2018.2; https://qiime2.org). Out of a total of 44 taxa analyzed, 13 bacterial taxa were considered important for the dairy industry (lactic acid bacteria, LAB, 5 taxa; and spoilage bacteria, 4) and for human (other probiotics, 2) and animal health (pathogenic bacteria, 2). The results revealed the transhumant group of cows transferred to summer highland pastures showed an increase in almost all the LAB taxa, bifidobacteria, and propionibacteria, and a reduction in spoilage taxa. All the metagenomic changes disappeared when the transhumant cows were moved back to the permanent indoor farm. The relationships between 17 microbial traits and 30 compositional and technological milk traits were investigated through analysis of correlation and latent explanatory factor analysis. Eight latent factors were identified, explaining 75.3% of the total variance, 2 of which were mainly based on microbial traits: pro-dairy bacteria (14% of total variance, improving during summer pasturing) and pathogenic bacteria (6.0% of total variance). Some bacterial traits contributed to other compositional-technological latent factors (gelation, udder health, and caseins).

Optimisation of soft cheese production conditions using papain as a plant-based enzyme by response surface methodology (RSM)

As the demand for cheese products increases, rennet enzyme supplied for cheese production is reduced due to the limited availability of ruminant stomach. In some countries, microbial coagulants have not been accepted for regular cheese manufacture because they are believed to result in a reduced yield and a lower quality product. Therefore, plant-based enzymes are one of the alternatives for animal-based enzyme substitution. Papain enzyme is chosen due to its capability of coagulating milk as it is a proteolytic enzyme. This study aimed to optimize the yield and viscosity of soft cheese by papain using response surface methodology (RSM) and to determine the physicochemical and textural properties of soft cheese. Experimental design was generated using RSM by MINITAB software version 19 with three selected variables including papain concentration (0.2 – 1 U/g), incubation time (1 – 5 hrs) and incubation temperature (30 – 50oC). The optimum condition for yield and viscosity of soft cheese was achieved at a papain concentration of 0.26 g, incubation time of 1.30 hrs and incubation temperature of 34.82oC, with the predicted yield and viscosity of 11.78 % and 4.77 Pa.s, respectively. The optimum condition was verified with the yield and viscosity obtained was 12.60% and 4.67 Pa.s, respectively. Since there was no significant difference (p>0.05) between the predicted and verified yield and viscosity values, thus it indicates that the predicted optimum condition by RSM can be accepted. Characterization of soft cheese produced using papain enzyme at optimum condition was also determined and compared with commercial soft cheese. There is a significant difference between these cheeses in terms of their physicochemical characteristics.

Genotype by environment interaction due to heat stress in Brown Swiss cattle

Due to its geographical position and a highly variable orography, Italy is characterized by several climatic areas and thus, by many different dairy cow farming systems. Brown Swiss cattle, in this context, are a very appreciated genetic resource for their adaptability and low metabolic requirement. The significant heterogeneity in farming systems may consist of genotype by environment (G × E) interactions with neglected changes in animals' rank position. The objective of this study was to investigate G × E for heat tolerance in Brown Swiss cattle for several production traits (milk, fat, and protein yield in kilograms; fat, protein, and cheese yield in percentage) and 2 derivate traits (fat-corrected milk and energy-corrected milk). We used the daily maximum temperature-humidity index (THI) range, calculated according to weather stations' data from 2008 to 2018 in Italy, and 202,776 test-day records from 23,396 Brown Swiss cows from 639 herds. Two different methodologies were applied to estimate the effect of the environmental variable (THI) on genetic parameters: (1) the reaction norm model, which uses a continuous random covariate to estimate the animal additive effect, and (2) the multitrait model, which splits each production pattern as a distinct and correlated trait according to the first (a thermal comfort condition), third (a moderate heat stress condition), and fifth (a severe heat stress condition) mean THI value quintile. The results from the reaction norm model showed a descending trend of the additive genetic effect until THI reached the value of 80. Then we recorded an increase with high extreme THI values (THI 90). Permanent environmental variance at increasing THI values revealed an opposite trend: The plot of heritability and the ratio of animal permanent environmental variance to phenotypic variance showed that when the environmental condition worsens, the additive genetic and permanent environmental component for production traits play a growing role. The negative additive genetic correlation between slope and linear random coefficient indicates no linear relationship between the production traits or under heat stress conditions, except for milk yield and protein yield. In tridimensional wireframe plots, the extreme margin decreases until a minimum of ∼0.90 of genetic correlation in the ECM trait, showing that the magnitude of G × E interaction is greater than the other traits. Genetic correlation values in Brown Swiss suggest the possibility of moderate changes in animals' estimated breeding value in heat stress conditions. Results indicated a moderate G × E interaction but significant variability in sire response related to their production level.

Mozzarella production with an addition of passion fruit (Passiflora edulis) juice

This research aimed to evaluate the effect of passion fruit juice on the mozzarella properties, determine suitable temperature and rennet concentration for casein coagulation and evaluate some quality properties of mozzarella products. The analytical results showed that the passion fruit mozzarella (PM) made with 3% (v:v) passion fruit juice (PJ), rennet concentration of 0.025% (v:v) at coagulation temperature of 37 ℃ had the cheese yield efficiency of 9.47%, total solid content of 55.86% and cheese solid yield of 45.94%. Furthermore, the protein, lipid and dry matter contents of the PM samples were 24.10%, 21.30% and 52.20%, respectively. The microbiological analysis showed that harmful pathogens including Escherichia coli, Salmonella spp, Listeria monocytogenes, Staphylococci were not detected in the samples. The microstructure images of PM samples had many sharp edges in a form of clusters. Moreover, the average acceptance score of PM samples (6.8/9.0) was higher than that of the first reference sample (5.9) which used citric acid for acidification process and Emborg mozzarella (RS2) (6.0). Thus, adding passion fruit juice to the mozzarella making-process positively affected quality properties of final product, especially the sensory properties (sense of smell). Therefore, applications of passion fruit juice in the dairy product industry are potential.

Yield and calo of the “Marija Zvijezda” Trappist cheese during ripening

This paper presents the results of research on yield and calo during ripening of the Trappist cheese. The cheese has been produced for more than 140 years by the monks of the Marija Zvijezda Monastery (Mariastern Abbey) in Banja Luka. In 2008 cheese production has been restored and the cheese has been presented to the market in cooperation with the “Livač” Cooperative. The Trappist cheese is made in the form of a wheel weighing 1.6-2.0 kg and it has a natural rind that is yellowish, thin, and smooth. The conditions and the way in which it ripens are specific and give a special flavour to the cheese. The duration of the ripening is a minimum of 90 days and it happens under specific conditions of humidity and temperature. The cheese ripens on wooden boards and it is rotated and cleaned manually. Its consistency is soft, elastic, mild, and it is easily cut. The cut is smooth without or with very little holes. It is characterized by a clean scent of milk, slightly salty, and it melts easily. The cheese yield calculated for the Trappist cheese is 12.81 %. The actual cheese yield obtained after 90 days of cheese ripening is 10.74 %. Cheese weight changes with ripening time and weight loss at the end of the production cycle is 0.322 kg or 15.85 %. The amount of whole milk needed for one kilogram of the final cheese product is about 9.35 kg.

Slower proteolysis in Cheddar cheese made from high-protein cheese milk is due to an elevated whey protein content.

A growing number of companies within the cheese-making industry are now using high-protein (e.g., 4-5%) milks to increase cheese yield. Previous studies have suggested that cheeses made from high-protein (both casein and whey protein; WP) milks may ripen more slowly; one suggested explanation is inhibition of residual rennet activity due to elevated WP levels. We explored the use of microfiltration (MF) to concentrate milk for cheese-making, as that would allow us to concentrate the casein while varying the WP content. Our objective was to determine if reducing the level of WP in concentrated cheese milk had any impact on cheese characteristics, including ripening, texture, and nutritional profile. Three types of 5% casein standardized and pasteurized cheese milks were prepared that had various casein:true protein (CN:TP) ratios: (a) control with CN:TP 83:100, (b) 35% WP reduced, 89:100 CN:TP, and (c) 70% WP reduced, 95:100 CN:TP. Standardized milks were preacidified to pH 6.2 with dilute lactic acid during cheese-making. Composition, proteolysis, textural, rheological, and sensory properties of cheeses were monitored over a 9-mo ripening period. The lactose, total solids, total protein, and WP contents in the 5% casein concentrated milks were reduced with increasing levels of WP removal. All milks had similar casein and total calcium levels. Cheeses had similar compositions, but, as expected, lower WP levels were observed in the cheeses where WP depletion by MF was performed on the cheese milks. Cheese yield and nitrogen recoveries were highest in cheese made with the 95:100 CN:TP milk. These enhanced recoveries were due to the higher fraction of nitrogen being casein-based solids. Microfiltration depletion of WP did not affect pH, sensory attributes, or insoluble calcium content of cheese. Proteolysis (the amount of pH 4.6 soluble nitrogen) was lower in control cheeses compared with WP-reduced cheeses. During ripening, the hardness values and the temperature of the crossover point, an indicator of the melting point of the cheese, were higher in the control cheese. It was thus likely that the higher residual WP content in the control cheese inhibited proteolysis during ripening, and the lower breakdown rate resulted in its higher hardness and melting point. There were no major differences in the concentrations of key nutrients with this WP depletion method. Cheese milk concentration by MF provides the benefit of more typical ripening rates.

Genetic Analysis of K-Casein Gene in Milk Protein of Bos Indicus Cattle

Purpose: Κ-casein, or kappa casein, is a mammalian milk protein involved in several important physiological processes. Chymosin splits K-casein into an insoluble peptide (para kappa-casein) and a water-soluble glycomacropeptide (GMP). GMP is responsible for increased efficiency of digestion, prevention of neonate hypersensitivity to ingested proteins, and inhibition of gastric pathogens. The gene underlying the production of kappa-casein in cow's Milk shows polymorphisms which affect the amount of protein produced. Higher levels of kappa-casein are associated with increased milk protein and casein content and better cheese yield. Method: The current study aimed to identify the genetic mutations among three indigenous cattle breeds of Sindh, Pakistan. A particular set of primers amplified the targeted area of the K-CASEIN gene after genomic DNA extraction from blood samples of the three cattle breeds, namely Cholistani cattle breed, Tharri, and Sahiwal. Findings: The amplified PCR products were sequenced using the ABI Genetic Analyzer 3500; a BioEdit version 7.2 was used to examine the sequencing data. Using the ensemble gene browser, blast analysis was also performed. Practical Implication: Results revealed 18 mutations in all 03 cattle breeds, including 07 mutations in the Cholistani cattle breed; the Tharri cattle breeds had 06 mutations, and the Sahiwal cattle breeds had 05 mutations. Results of this study of the K-CASEIN gene suggested that Cholistani cattle breeds are more genetically varied than the Sahiwal cattle breeds. Conclusion: Furthermore, the Sahiwal cattle breed is more diverse than the Thari cattle breed for the said gene. Keywords: K-Casein gene, Sahiwal cattle breed, Thari cattle breed, Cholistani cattle breed, Polymorphism

Milk-Gelling Properties of Proteases Extracted from the Fruits of Solanum Elaeagnifolium Cavanilles.

There is little information on the milk coagulation process by plant proteases combined with chymosins. This work is aimed at studying the capability of protease enclosed in the ripe fruits of Solanum elaeagnifolium (commonly named trompillo) to form milk gels by itself and in combination with chymosin. For this purpose, proteases were partially purified from trompillo fruits. These proteases had a molecular weight of ~60 kDa, and results suggest cucumisin-like serine proteases, though further studies are needed to confirm this observation. Unlike chymosins, trompillo proteases had high proteolytic activity (PA = 50.23 UTyr mg protein−1) and low milk-clotting activity (MCA = 3658.86 SU mL−1). Consequently, the ratio of MCA/PA was lower in trompillo proteases (6.83) than in chymosins (187 to 223). Our result also showed that milk gels formed with trompillo proteases were softer (7.03 mPa s) and had a higher release of whey (31.08%) than the milk gels clotted with chymosin (~10 mPa s and ~4% of syneresis). However, the combination of trompillo proteases with chymosin sped up the gelling process (21 min), improved the firmness of milk gels (12 mPa s), and decreased the whey release from milk curds (3.41%). Therefore, trompillo proteases could be combined with chymosin to improve the cheese yield and change certain cheese features.

Prediction of fresh and ripened cheese yield using detailed milk composition and udder health indicators from individual Brown Swiss cows.

The composition of raw milk is of major importance for dairy products, especially fat, protein, and casein (CN) contents, which are used worldwide in breeding programs for dairy species because of their role in human nutrition and in determining cheese yield (%CY). The aim of the study was to develop formulas based on detailed milk composition to disentangle the role of each milk component on %CY traits. To this end, 1,271 individual milk samples (1.5 L/cow) from Brown Swiss cows were processed according to a laboratory model cheese-making procedure. Fresh %CY (%CYCURD), total solids and water retained in the fresh cheese (%CYSOLIDS and %CYWATER), and 60-days ripened cheese (%CYRIPENED) were the reference traits and were used as response variables. Training-testing linear regression modeling was performed: 80% of observations were randomly assigned to the training set, 20% to the validation set, and the procedure was repeated 10 times. Four groups of predictive equations were identified, in which different combinations of predictors were tested separately to predict %CY traits: (i) basic composition, i.e., fat, protein, and CN, tested individually and in combination; (ii) udder health indicators (UHI), i.e., fat + protein or CN + lactose and/or somatic cell score (SCS); (iii) detailed protein profile, i.e., fat + protein fractions [CN fractions, whey proteins, and nonprotein nitrogen (NPN) compounds]; (iv) detailed protein profile + UHI, i.e., fat + protein fractions + NPN compounds and/or UHI. Aside from the positive effect of fat, protein, and total casein on %CY, our results allowed us to disentangle the role of each casein fraction and whey protein, confirming the central role of β-CN and κ-CN, but also showing α-lactalbumin (α-LA) to have a favorable effect, and β-lactoglobulin (β-LG) a negative effect. Replacing protein or casein with individual milk protein and NPN fractions in the statistical models appreciably increased the validation accuracy of the equations. The cheese industry would benefit from an improvement, through genetic selection, of traits related to cheese yield and this study offers new insights into the quantification of the influence of milk components in composite selection indices with the aim of directly enhancing cheese production.

Composition and cheese suitability of milk of cows of different breeds

The aim of this work was to compare the quality of milk and its suitability for processing into cheese in cows of the local Ukrainian black-and-white dairy (UBW) breed and their crossbreeds with the Swiss breed. The research was conducted on a commercial farm in Vinnytsia region. The first farm keeps purebred cows of the Ukrainian black-and-white dairy breed and crossbreeds of the first generation obtained as a result of crossing with the Brown Swiss breed. Two groups (purebred and local) analog cows were formed with 20 heads each. It was found that crossbreeding had a positive effect on the content of fat and protein in milk in crossbreeds UBW and Brown Swiss cows, these values were 0.21 and 0.13% higher than in purebred cows. At the same time, the crossbreeds lost some of their productivity - the average daily yield of UBW and Brown Swiss cows was 1.83 kg lower than that of purebred counterparts. The crossbreeds of UBW and Brown Swiss cows were dominated by purebred analogues in terms of energy value of 1 kg of milk and theoretically possible yield of rennet cheese by 0.141 MJ and 0.53 kg. The duration of the coagulation phase of milk obtained from crossbred cows was shorter than that of purebred analogues: in crossbreeds of UBW and Brown Swiss cows by 1.23 minutes. Samples of milk obtained from crossbreeds had the highest class on the characteristics of the rennet clot. Out of 20 studied samples of milk of UBW cows of breed 15 samples (75%) are referred to I and 5 (25%) - to II class; in the milk of UBW and Brown Swiss breeds of cows 17 (85%) - up to I and 3 (15%) - up to II class.

Особенности получения и применения мицеллярного казеина в технологии молокоемких белковых продуктов

The modern food industry sees raw milk as a source of functional ingredients. Technologies of protein ingredients have a great scientific and practical importance because membrane fractionation methods preserve the native structure and properties of protein components. The resulting proteins have good fat profile, moisture retention, and emulsification characteristics, as well as perform some useful technological functions in food systems. They have no status of food additives and can be applied in various branches of food production. Unfortunately, the Russian food industry has no such technologies of its own. This article introduces some technological recommendations for the p roduction of domestic micellar casein concentrate.
 The research involved skim milk, commercial micellar casein concentrates from various manufacturers, curd samples with 9.0% of fat in dry matter, and Rossiysky cheese produced according to traditional formulation and technology. The experiment relied on standard research methods of physical and chemical analysis to establish the chemical composition of the samples, e.g., fractional composition of skim milk proteins, grain-size distribution, amino acid profile, etc.
 The study involved a comparative analysis of the chemical composition, as well as functional and technological properties of commercial micellar casein concentrates from various manufacturers. A set of experiments made it possible to define the thermal effect on raw material and to predict the prospects for usage of the new technology. Samples with a high ratio of casein:whey proteins and a moderately high heat treatment increased the curd and cheese yield by 10–12% in comparison with the traditional formulation. Samples with the maximal concentration of undenatured milk-serum protein nitrogen increased the yield of protein dairy products by 2–3% in comparison with other samples of micellar casein concentrates. The ratio of casein:whey proteins was 80:20 in skim milk obtained at PJSC Dairy “Voronezhsky”. The optimal pore diameter was ≥ 15 nm. As for the microbiological properties, QMA&OAMO was 6×104 CFU/dm3, and no pathogenic microorganisms were detected.
 Therefore, low-temperature pasteurization proved feasible at ≤ 76 ± 2°C and 10–15 s of hold time. The micellar casein concentrate added certain functional and technological properties to the finished product, depending on the specific application scope. 
 The new technology will enable the domestic food industry to ov ercome the existing import dependence.

Low-density SNP panel for efficient imputation and genomic selection of milk production and technological traits in dairy sheep.

The present study aimed to ascertain how different strategies for leveraging genomic information enhance the accuracy of estimated breeding values for milk and cheese-making traits and to evaluate the implementation of a low-density (LowD) SNP chip designed explicitly for that aim. Thus, milk samples from a total of 2,020 dairy ewes from 2 breeds (1,039 Spanish Assaf and 981 Churra) were collected and analyzed to determine 3 milk production and composition traits and 2 traits related to milk coagulation properties and cheese yield. The 2 studied populations were genotyped with a customized 50K Affymetrix SNP chip (Affymetrix Inc.) containing 55,627 SNP markers. The prediction accuracies were obtained using different multitrait methodologies, such as the BLUP model based on pedigree information, the genomic BLUP (GBLUP), and the BLUP at the SNP level (SNP-BLUP), which are based on genotypic data, and the single-step GBLUP (ssGBLUP), which combines both sources of information. All of these methods were analyzed by cross-validation, comparing predictions of the whole population with the test population sets. Additionally, we describe the design of a LowD SNP chip (3K) and its prediction accuracies through the different methods mentioned previously. Furthermore, the results obtained using the LowD SNP chip were compared with those based on the 50K SNP chip data sets. Finally, we conclude that implementing genomic selection through the ssGBLUP model in the current breeding programs would increase the accuracy of the estimated breeding values compared with the BLUP methodology in the Assaf (from 0.19 to 0.39) and Churra (from 0.27 to 0.44) dairy sheep populations. The LowD SNP chip is cost-effective and has proven to be an accurate tool for estimating genomic breeding values for milk and cheese-making traits, microsatellite imputation, and parentage verification. The results presented here suggest that the routine use of this LowD SNP chip could potentially increase the genetic gains of the breeding selection programs of the 2 Spanish dairy sheep breeds considered here.

Development of a duplex qPCR assay with locked nucleic acid probes for A, B and E kappa-casein variants detection

Milk proteins determine important milk technological characteristics. Among caseins, Ƙ-casein has been correlated with fat and protein content and cheese yield. Fourteen Ƙ-caseins variants have been described but the alleles A, B and E are the most important ones due to their frequency and/or influence on the technological aptitudes of milk. Therefore, in the present study two different duplex qPCR assays with locked nucleic acid probes (for positions 13104 and 13124 of the Ƙ-casein gene) were developed for the detection of A, B and E variants. Firstly, DNA isolation method from milk somatic cells and hair was optimised. The developed 13124-qPCR assay showed an increased sensitivity reaching up to 6.7 copies DNA copies/reaction at a 95% confidence level with A, B and E alleles reference samples. The 13104-qPCR assay reached up to 6.7 DNA copies/reaction for A allele reference sample and 67 DNA copies/reaction for B and E samples. Intra-assay variation results were below 6%. Applicability was determined using DNA samples from animals with known genotype for Ƙ-casein (AA, AB, BB, BE, AE, EE) and both assays were able to discriminate among the six genotypes with 100% accuracy. Thus, this qPCR method represents a sensitive and rapid option for the detection of Ƙ-casein alleles in both hair and milk samples.

Prediction accuracies of cheese-making traits using Fourier-transform infrared spectra in goat milk

The objectives of this study were to explore the use of Fourier-transform infrared (FITR) spectroscopy on 458 goat milk samples for predicting cheese-making traits, and to test the effect of the farm variability on their prediction accuracy. Calibration equations were developed using a Bayesian approach with three different scenarios: i) a random cross-validation (CV) [80% calibration (CAL); 20% validation (VAL) set], ii) a stratified CV [(SCV), 13 farms used as CAL, and the remaining one as VAL set], and iii) a SCV where 20% of the goats randomly selected from the VAL farm were included in the CAL set (SCV80). The best prediction performance was obtained for cheese yield solids, justifying for its practical application at population level. Overall results were similar to or outperformed those reported for bovine milk. Our results suggest considering specific procedures for calibration development to propose reliable tools applicable along the dairy goat chain.