Dairy

Dairy proteins are potential and multipurpose ingredients used to prepare various food products. It exhibits many beneficial functionalities and bioactivities in the processing of food products. All the functionalities of different dairy proteins depend on their peculiar structural characteristics. So, the present study aimed to characterize high-protein powders with different matrices (milk protein concentrate (MPC), rennet casein (RCN), micellar casein concentrate (MCC), whey protein isolate (WPI), and native whey concentrate (NWC)) for their composition, handling, and reconstitution properties, and microstructure and compared them with whole milk powder (WMP) and skim milk powder (SMP). The bulk density of the high-protein powders was significantly (p < 0.05) lower than WMP and NFDM. Due to the low bulk density of the high-protein powders, the wettability of these powders in the water was very high. Microstructural analysis of powders by scanning electron microscopy reveals that the high-protein powder had tetrahedron-to-polyhedron-shaped particles depending on the protein level. The idea regarding the powder’s morphology might be helpful for further improvement in the production processes to modify the functional properties of high-protein milk powders. Full article

In this study, the microbiological quality of traditionally fermented milk from Northern Uganda and Western Kenya was analysed. Six samples of typical traditionally fermented milk were collected randomly from traditional cattle keepers in Karamojong (UG 1) and Acholi (UG 2) in Northern Uganda and Kalenjin in Western Kenya (KE). The microbial quality of the collected samples was assessed through the use of conventional methods for total aerobic mesophilic bacteria, total coliform, lactic acid bacteria, Staphylococcus aureus, Listeria monocytogenes, yeasts, and mould counts. The mean aerobic mesophilic bacterial counts were 5.14 × 10⁹ coliform forming units (cfu)/mL. The mean counts for mesophilic lactobacilli ranged from 10⁶ to 10⁸ cfu/mL. The mean thermophilic lactobacilli count ranged from 10⁷ to 10⁹ cfu/mL, while the mean thermophilic lactococci counts ranged from 10⁶ to 10⁹ cfu/mL. On the other hand, the Streptococci counts were between 10⁶ and 10⁸ cfu/mL. The mean count for the non-sorbitol E. coli was 3.87 × 10³ cfu/mL. These results suggest that although the pH of the traditional yoghurt in this study was low, the acidity was not sufficient to inhibit growth of microorganisms in the product. Although it is difficult to avoid the microbial contamination of milk during milking, it is of the utmost importance to maintain a very high level of hygiene in dairy farming practices, and the correct cleaning of teats during milking is very important for good udder health and optimum milk quality, and to ensure safety. The results regarding microbial contamination pose public health concerns, and therefore the appropriate government agencies must pay attention to ensure that the environment in which yoghurt is produced is in the best condition to reduce contamination. Full article

The study examined the relationship between milk yield and udder morphology traits in White Fulani cows. Fifty-eight apparently healthy cows in early lactation at 2nd, 3rd, and 4th parity were used in the study. The data obtained from the cows were test day milk yield (TDMY) from single milking and udder morphology traits comprising udder length (UL), udder width (UW), udder depth (UD), fore teat length (FTL), rear teat length (RTL), fore teat diameter (FTD), and rear teat diameter (RTD). There was no significant effect of parity on TDMY or the udder morphology traits. Phenotypic correlations between TDMY, UL, UW, and UD were positive and significant. Notably, phenotypic correlations between UL and TDMY at different parities were the strongest. Teat measurements had no significant correlation with TDMY. Stepwise and principal component regressions were implemented to assess the relationship between milk yield and udder morphology traits. Interestingly, UL was the only trait that entered the reduced models. The results suggest a probable genetic correlation between milk yield and udder length. Therefore, since udder conformation traits are heritable, when selecting for udder length in White Fulani cows, a correlated response in milk yield is expected. Full article

The objective of this three-treatment, 12-week study (involving 69 dairy cows) was to test three methods of concentrate allocation on milk production efficiency. All treatments were offered a basal mixed ration of grass silage and concentrates, with additional concentrates offered to individual cows based on either milk yield alone (Control), milk energy output (Precision 1) or energy intake and milk energy output (Precision 2). Concentrate requirements were calculated and adjusted weekly. Control cows had lower concentrate dry matter intake (DMI; p = 0.040) and milk protein content (p = 0.003) but yield of milk and energy-corrected milk (ECM), energy balance, bodyweight and condition score were unaffected by treatment. Efficiency measures such as ECM/DMI and ECM/metabolizable energy intake were also unaffected by treatment. Less concentrates were used per kg ECM yield in the Control compared to the Precision treatments (p < 0.001). In conclusion, accounting for individual cow milk composition or milk composition combined with individual cow energy intake did not improve production efficiency compared to an approach based on individual cow milk yield only. Full article

Blue cheeses are those whose matrix is veined with a blue, blue-grey, or blue-green colour due to the development of Penicillium roqueforti. There are more than 45 varieties of blue cheese produced worldwide, with some distinct features, although the manufacture process is similar. In addition to P. roqueforti, complex microbial populations interact and succeed throughout the manufacturing and ripening at the cheese’s surface (the rind) and interior (matrix). The microbiota of blue cheeses is made up of a vast array of both prokaryotic and eukaryotic microorganisms. Acidification of the curd relies on the action of lactococci and other lactic acid bacteria (LAB) species. The ripened cheeses’ final quality and shelf-life properties largely depend on the enzymatic systems of the components of the microbiota, particularly on those of LAB, P. roqueforti, and yeast species. Proteolysis is the most complex and important primary biochemical process involved in blue-veined cheeses during ripening, with P. roqueforti being considered the main proteolytic agent. Lipolysis is also strong, originating, among other compounds, ketones, which are the main aroma compounds in blue-veined cheeses. In addition, several bioactive compounds are produced during ripening. The biochemical activities, mainly of microbial origin, are responsible for the sensory characteristics of these very appreciated cheese varieties worldwide. Full article

The ability to measure and capture real-time unit operational data has significant benefits during dairy processing, whether it is the basics, such as measuring temperature, pressure, and flow rates, or more recent developments in the case of in-line viscosity and product-compositional measurements. This rapid data collection has helped increase profitability by reducing energy costs, minimizing product loss, and allowing automated control. Advances in technology have allowed for in-line measurements of the composition and some physical attributes such as particle size and viscosity; however, an attribute that spans both compositional and physical attributes is pH, directly influenced by composition but also environments, such as temperature and dry matter content. pH is measured for a plethora of reasons, such as a measure of milk quality (microbial spoilage), acidification of casein, cheese production, maintaining optimum conditions during protein hydrolysis, etc. However, very little is published on the fundamentals of pH and pH measurement in dairy processing; rather, it is usually a cause-and-effect phenomenon. This review visits one of the oldest analytical considerations in the dairy industry and re-examines how it is affected by product composition and processing conditions. Full article

Evaluation of dairy cow exposure to DON can generally be managed through analyses of feed or physiological specimens for DON residues. The latter enables a diagnosis not only on an individual basis but also on a herd basis. For this purpose, on the basis of published data, linear regression equations were derived for blood, urine, milk, and bile relating DON residue levels as predictor variables to DON exposure. Amongst the matrices evaluated, blood was identified to reflect the inner exposure to DON most reliably on toxicokinetic backgrounds, which was supported by a linear relationship between DON residues in blood and DON exposure. On the basis of this, and because of extended blood data availability, the derived regressions were validated using internal and external data, demonstrating a reasonable concordance. For all matrices evaluated, the ultimately recommended linear regression equations intercepted the origin and enabled the prediction of the DON exposure to be expected within the prediction intervals. DON exposure (µg/kg body weight/d) can be predicted by multiplying the DON residues (ng/mL) in blood by 2.52, in urine by 0.022, and in milk by 2.47. The span of the prediction intervals varied according to the dispersion of the observations and, thus, also considered apparent outliers that were not removed from the datasets. The reasons were extensively discussed and included toxicokinetic aspects. In addition, the suggestions for sample size estimation for future characterization of the mean exposure level of a given herd size were influenced by expectable variation in the data. It was concluded that more data are required for all specimens to further qualify the preliminary prediction equations. Full article

The objectives of this study were to investigate the effect of newly developed blend-pelleted products based on carinata meal (BPPCR) or canola meal (BPPCN) in combination with peas and lignosulfonate on ruminal fermentation characteristics, degradation kinetics, intestinal digestion and feed milk values (FMV) when fed to high-producing dairy cows. Three dietary treatments were Control = control diet (common barley-based diet in western Canada); BPPCR = basal diet supplemented with 12.3%DM BPPCR (carinata meal 71.4% + pea 23.8% + lignosulfonate4.8%DM), and BPPCN = basal diet supplemented with 13.3%DM BPPCN (canola meal 71.4% + pea 23.8% + lignosulfonate 4.8%DM). In the whole project, nine mid-lactating Holstein cows (body weight, 679 ± 124 kg; days in milk, 96 ± 22) were used in a triplicated 3 × 3 Latin square study for an animal production performance study. For this fermentation and degradation kinetics study, the experiment was a 3 × 3 Latin square design with three different dietary treatments in three different periods with three available multiparous fistulated Holstein cows. The results showed that the control diet was higher (p < 0.05) in total VFA rumen concentration (138 mmol/L) than BPPCN. There was no dietary effect (p > 0.10) on the concentration of rumen ammonia and ruminal degradation kinetics of dietary nutrients. There was no significant differences (p > 0.10) among diets on the intestinal digestion of nutrients and metabolizable protein. Similarly, the feed milk values (FMV) were not affected (p > 0.10) by diets. In conclusion, the blend-pelleted products based on carinata meal for a new co-product from the bio-fuel processing industry was equal to the pelleted products based on conventional canola meal for high producing dairy cattle. Full article

Listeria monocytogenes is an opportunistic pathogen that affects specific groups of individuals, with a high mortality rate. The control of L. monocytogenes in dairy industries presents particular challenges, as this bacterium is capable of adhering and forming biofilms, as well as thriving at refrigerated temperatures, which enables it to persist in harsh environments. The consumption of dairy products has been linked to sporadic cases and outbreaks of listeriosis, and L. monocytogenes is frequently detected in these products in retail stores. Moreover, the bacterium has been shown to persist in dairy-processing environments. In this work, we review the main characteristics of L. monocytogenes and listeriosis, and highlight the factors that support its persistence in processing environments and dairy products. We also discuss the main dairy products involved in outbreaks of listeriosis since the early 1980s, and present control measures that can help to prevent the occurrence of this pathogen in foods and food-processing environments. Full article

Although traditional ryegrass pastures are still commonly used, they require intense management and input and do not perform well during the summer months. Multispecies systems have been recognised as more sustainable, needing less fertiliser and being tolerant to drought and heat. While data on monoculture system fat composition exist, information for multispecies is scarce. The present study compared the fatty acid (FA), carotenoid and fat-soluble composition of a multispecies system (consisting of perennial ryegrass, timothy, white clover, red clover, chicory and plantain) (MULTI) with two other conventional grazing systems (monoculture perennial ryegrass (PRG) and a binary mixture of perennial ryegrass and white clover (PRG+WC)) over the Irish late-summer grazing season of dairy cattle (July–September). The results showed that the three systems had similar levels of FAs (p > 0.05), with mean α-linolenic acid values of 20.00 mg/g in PRG, 18.51 mg/g in PRG+WC, and 17.90 mg/g in MULTI and mean linoleic acid values of 3.84 mg/g in PRG, 4.16 mg/g in PRG+WC, and 4.39 mg/g in MULTI. Fourfold and twofold increases in the concentrations of α-linolenic acid and linoleic acid, respectively, were observed throughout July–September. Variations in stearic acid concentrations were not significant (p > 0.05), and palmitic acid concentrations increased over time (p < 0.05). The average values of lutein (36.68 mg/kg in PRG, 31.26 mg/kg in PRG+WC, and 35.75 mg/kg in MULTI) and α-tocopherol (2.28 mg/kg in PRG, 1.49 mg/kg in PRG+WC, and 1.83 mg/kg in MULTI) were similar among the grazing systems (p > 0.05), and the average β-carotene value was 25% higher in monoculture ryegrass (140.74 mg/kg) than in the multispecies (102.51 mg/kg) (p < 0.05). Nonetheless, the levels of β-carotene found in the multispecies were still above the recommended intake required for ruminants. In conclusion, multispecies pastures could be included in dairy cattle production systems as a sustainable alternative to traditional pastures while also providing typically adequate sources of fats for animal diets. Full article

Despite routine supplementation of dairy cattle with vitamins with antioxidant functions, such as α-tocopherol, the high energy demand of the transition period creates a pro-oxidant state that can overcome antioxidant defenses and damage macromolecules. Known as oxidative stress, this condition impairs host immune defenses, predisposing cattle to disease and causing dysfunctional inflammation through a dysregulated production of lipid inflammatory mediators known as oxylipids. Non-α-tocopherol analogs of vitamin E have functions in other species that limit oxidative stress and dysfunctional inflammation but have largely remained unstudied in cattle. As non-α-tocopherol analogs of vitamin E have functions similar to α-tocopherol yet are more rapidly metabolized, they may provide further antioxidative functions with a reduced risk for adverse effects. Indeed, in vitro and in vivo evidence in cattle show a strong safety profile of most non-α-tocopherol analogs, and by several measures, non-α-tocopherol analogs present equally or more potent antioxidative activities than α-tocopherol alone. Further, vitamin E analogs are shown to compete with certain fatty acids for enzymatic metabolism, which may impact proinflammatory mediator production. Given that non-α-tocopherol analogs of vitamin E reduce the production of pro-inflammatory mediators and act as potent antioxidants, their safety and efficacy for these purposes should be further evaluated in cattle. Full article

In recent years, there has been an unprecedented increase in the demand for fermented dairy products due to medical recommendations and lifestyle preferences. Cultured buttermilk, as an ancient fermented dairy beverage, is an appropriate product choice in this context. This study presents a novel cultured buttermilk formulated by fortification with high protein microalgae Spirulina platensis, thus making it valuable and attractive because of its antioxidant properties. The fermentation process, nutraceutical properties, and sensory characteristics of developed cultured buttermilk with various concentrations of Spirulina (0.25, 0.5, and 1%) were compared with the control sample (0% Spirulina buttermilk). Different concentrations of Spirulina in buttermilk result in a significant increase in chlorophyll and carotenoid content, boosting its antioxidant properties. The study also evaluated the prebiotic properties of Spirulina, thus, demonstrating its ability to promote a healthy digestive system. It was found that the addition of 0.25% Spirulina was able to ferment the product more quickly and retained the sensory acceptability of the finished product. The protein content, free radical scavenging activity, chlorophyll, carotenoid, and total phenolic content of 0.25% Spirulina-fortified buttermilk was 1.83%, 48.19%, 30.9 mg/g, 8.24 mg/g, and 4.21 mg/g GAE, respectively. Based on the results obtained, it was concluded that cultured buttermilk with a high nutritional value and functional health benefits can be developed by fortification with 0.25% Spirulina as a natural ingredient. Full article

Whey cheeses have been produced from the very early steps of cheesemaking practices as a sustainable way to utilize whey, which is the main by-product of cheesemaking. Traditional whey cheeses, manufactured with similar processes, are Ricotta, Ricotta salata or Ricottone, and Ricotta fresca in Italy; Anthotyros, Myzithra, Manouri, Xynomyzithra, and Urda in Greece; Urda in Serbia and Romania as well as in other countries such as Israel; Lor in Turkey; Anari in Cyprus; Skuta in Croatia and Serbia; Gjetost and Brunost in Norway; Mesost and Messmör in Sweden; Mysuostur in Iceland; Myseost in Denmark; Requeijão in Portugal; and Requesón in Spain and Mexico. The production of whey cheese is based on the denaturation of whey proteins by heating to 88–92 °C. The specific processing conditions and aspects of the microbiology of whey cheeses are discussed. The special characteristics of whey cheeses, which are high pH and high moisture content, make them susceptible to microbial growth. Due to the limited shelf life of these products, extended research has been carried out to extend the shelf life of whey cheese. The sustainable preservation approaches, such as modified atmosphere packaging, addition of herbs and/or plant extracts, and bio-preservation methods are reviewed. Moreover, novel whey cheeses focused on functional properties have developed during the last 10 years. Full article

In the past few years, Jersey cow milk has been considered an effective commodity for the production of dairy products, such as cheese and yoghurts, due to its high nutrient density. Initially, the microbial safety and physicochemical properties of pasteurized milk from Jersey cows raised in Evrofarma S.A. dairy facilities were monitored and compared to Holstein Friesian milk over a six-month period. Subsequently, a new traditional-type Greek yoghurt was prepared using Jersey cow milk andthe physicochemical, microbiological and sensory properties were monitored throughout its shelf time and compared to commercially available traditional-type Greek yoghurts made with Milk Protein Concentrate powder (MPC)-fortified Holstein Friesian milk. Our study confirmed the significantly higher fat (29.41%), protein (20.6%) and calcium content (19.9%) compared to Holstein Friesian milk. The new yoghurt demonstrated several technological advantages and shared similar physicochemical properties with the commercially available products. Importantly, high protein concentration (4.03 g/100 g) was documented without the addition of MPC. Finally, the new yoghurt was accepted during the preliminary sensory evaluation, while similar scores with the commercially available products were noted during the texture, flavour, aroma and overall quality assessment. Full article

Blue-veined cheeses in general undergo a pronounced lipolysis. The aim of this work was to determine the evolution of free fatty acids (FFA) in Valdeón cheese during ripening, comparing cheeses made from raw and pasteurized milk. The effect of season on the evolution of FFA in pasteurized milk cheeses was also studied. Cheeses made with raw milk showed the highest concentrations of FFA, reaching values of 23,081.9 mg 100 g⁻¹ dry matter at the end of ripening, compared to the values of cheeses made with pasteurized milk (7327.1 mg 100 g⁻¹ dry matter), in both cases with a predominance of oleic and palmitic acids. However, pasteurization did not affect the FFA profile of the cheeses. Regarding the cheeses made with pasteurized milk in different seasons, the highest FFA concentration was reached in cheeses made in summer after 30 days of ripening. The season also influenced the FFA profile and thus the concentration of short-, medium- and long-chain fatty acids in relation to total FFA. There were no significant differences in sensory analysis between cheeses made from raw and pasteurized milk. Full article

The objective of this retrospective case study was to understand the effects of eliminating free-stall lock-up time during 21 days postpartum on milk yield, reproductive performance, and health events at a large dairy herd. A group of 200 cows were selected as the treatment (TRT) group, which did not receive a lock-up time during early lactation, and a separate group of 200 cows served as the control (CON) group, which received on average 2 h/day of lockup time. The TRT group had greater milk yield (mean ± SE) on the third monthly milk test day (33.1 ± 0.75 vs. 29.9 ± 1.22; p = 0.04) and tended to have greater milk yield on the second test day (38.3 ± 1.55 vs. 39.1 ± 0.79; p = 0.06) compared to the CON cows. Milk fat% (mean ± SE) was greater in the TRT group than in the CON group on the first monthly milk test (3.65 ± 0.06 vs. 3.31 ± 0.12, p = 0.01). The TRT group had lower linear somatic cell scores on the first monthly milk test day compared to the CON group (2.6 ± 0.24 vs. 3.2 ± 0.11; p = 0.01). Cows in the TRT group had lower days in milk at first breeding (DIMFB) (66.2 ± 3.7 vs. 76.7 ± 2.9; p = 0.02) and were confirmed pregnant earlier as indicated by smaller days in milk to pregnancy (DIMPREG) (96.9 ± 12.32 vs. 112.1 ± 5.5; p < 0.01). Cows in the TRT group also had fewer incidences of all health events combined (13% vs. 30.5%; p < 0.001), lameness (3% vs. 9.5%; p = 0.01), and mastitis (3% vs. 16%; p < 0.001). We conclude that eliminating the stall lockup may have contributed to the increased milk yield, health, and reproductive performance of dairy cows in this dairy herd. Future prospective cohort studies are needed to further assess the potential effect of eliminating lock up time on cow performance. Full article

Ruminant milk is an essential part of the human diet and is widely accepted as a major nutrient source in developing countries. However, the polar and neutral lipid content variation in milk fat globules (MFG)among cow, goat, and water buffalo is poorly understood. This study used high-performance thin layer chromatography to identify and quantify five major polar (PL) and three neutral lipids (NL) from the MFG of cow, goat, and water buffalo. Optimal separation was achieved for PLs using chloroform: methanol: water (65:25:4), and hexane: diethyl ether: acetic acid (70:30:1) for NLs. The lower detectable (0.12 to 1.53 μg/mL) and quantification (0.12 to 1.53 μg/mL) limits indicated the high sensitivity of the method. Quantification at 540 nm showed the highest abundance of phosphatidylethanolamine and triglycerides. Fat globules were further characterized for size and microstructural properties, which revealed smaller globules in goats (0.99 ± 0.04 μm) than cows (1.85 ± 0.03 μm) and water buffaloes (2.91 ± 0.08 μm), indicating a negative correlation with PL but a positive correlation with NL. The variation in lipid quantity among different animal species suggests more research to support their selection as a suitable source for developing functional food to impact human health positively. Full article

Particle size is not only important for the sensory perception of fat-free fermented concentrated milk products, but also for processing operations because of the direct relationship with apparent viscosity. The aim of this study was to apply inline particle size analysis using focused beam reflectance measurement (FBRM) to obtain real-time information regarding the particle size of a fat-free fermented concentrated milk product, namely, fresh cheese. By comparing inline particle size data to offline particle size, apparent viscosity, protein content and processing information, the potential to use inline particle size analysis as a process monitoring and control option during fresh cheese production was assessed. Evaluation of inline particle size after fermentation and before further processing, e.g., after a buffering tank, shows promise as a means to control variance of product entering downstream processing and, thus, improve final product consistency over time. Measurement of inline particle size directly before filling could allow for precise control of final product characteristics by the use of mechanical or mixing devices placed before the inline measurement. However, attention should be given to the requirements of the inline measurement technology for accurate measurement, such as product flow rate and pressure. Full article