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This work elucidates the mechanism involved in the effect of varying sterilization intensities on RDC thickening via comparative analysis of the changes in the composition and structure of RDC interfacial protein after storage at 4 °C and at 25 °C. The results showed that pasteurized RDCs (75 °C for 16 s, 90 °C for 5 min) and high-temperature sterilized RDCs (105 °C for 3 min, 115 °C for 7 min and 121 °C for 7 min) did not thicken during storage at 25 °C, and had lower viscosities and higher Ca2+ concentrations than those stored at 4 °C. Whey protein (WP) aggregates were found to have been adsorbed at the interface of high-temperature treated RDCs stored at 4 °C, leading to the aggregation of fat globules and, consequently, reversible thickening. However, high-temperature sterilized RDCs underwent into irreversible thickening at 10 d, 7 d and 3 d. This phenomenon was attributed to the large amount of heat-induced whey protein and κ-casein complex that was absorbed on the oil-water interface, with Ca2+ bonded to form bridging flocculation, which altered the secondary structure of the interfacial protein to one with increased β-sheet content and decreased random coil content. • Thickening rate increased with increasing sterilization intensity. • Reversible thickening was due to the aggregation of fat globules. • Irreversible thickening was associated with interfacial protein flocculation. • More β-sheet and less random coil structure aggravated irreversible thickening. [ABSTRACT FROM AUTHOR]

Simple Summary: The demand for the milk and dairy products keeps growing due to the growing population, the rising consumption of protein-enriched food, and other factors. Thus, enhancing milk production becomes a critical issue for the world. Of all the factors related to promoting milk production, nutrient supplementation is widely investigated. First, researchers provided mammary epithelial cells or animals with appropriate nutrients such as amino acids, peptides, lipids, carbohydrates, and others. Then, they detected the increase in milk protein expression or milk production. Finally, the researcheres further investigated the essential pathways on which the nutrients act. As much effort has been made on this topic, we summarize recent work on enhancing milk production through nutrient supplements. We hope this review provides a systematic reference for researchers in related fields and can help understand the mechanism of milk production promotion by nutrients. The enhancement of milk production is essential for dairy animals, and nutrient supplements can enhance milk production. This work summarizes the influence of nutrient supplements—including amino acids, peptides, lipids, carbohydrates, and other chemicals (such as phenolic compounds, prolactin, estrogen and growth factors)—on milk production. We also attempt to provide possible illuminating insights into the subsequent effects of nutrient supplements on milk synthesis. This work may help understand the strategy and the regulatory pathway of milk production promotion. Specifically, we summarize the roles and related pathways of nutrients in promoting milk protein and fat synthesis. We hope this review will help people understand the relationship between nutritional supplementation and milk production. [ABSTRACT FROM AUTHOR]

The effectiveness of cattle selection for quantitative and qualitative traits that are of economic importance in dairy cattle breeding largely depends on the identification of the genes that control these traits, as well as their allelic polymorphisms. One such gene is the LGB gene that encodes the protein beta-lactoglobulin. This review provides brief information about the structure and biological role of this protein and its gene polymorphism. An analysis of the literature data of various studies was carried out, which made it possible to identify and evaluate the effect of the two most common alleles of the LGB gene (A and B) on the efficiency indicators of dairy production. [ABSTRACT FROM AUTHOR]

The objective of this study was to compare milk protein, amino acid and free fatty acid content among two kinds of milk with different foaming properties, used in coffee. For the milk protein, a significant difference between milk types was found in β-lactoglobulin (β-LG) and α-lactalbumin (α-LA), but not in casein content. The content of β-LG and α-LA in milk with the high foaming property of 70-96% (milk C) was significantly higher than that of milk with the low foaming property 30-48% (milk E). In terms of essential amino acids (EAA), the leucine (Leu) and lysine (Lys) were present in the highest quantities, and of the nonessential amino acids (NEAA), glutamic acid (Glu) had the highest content. Of the free fatty acids (FFA), the saturated fatty acids(SFA) content in milk C was lower, and unsaturated fatty acid (UFA) content was higher, than in milk E. The highest FFA contents were observed for C14:0, C16:0 and C18:1, and the C16:0 content in milk E was significantly higher than in milk C. In brief, although whey protein improves foaming, but the presence of FFAs strongly impairs foaming. [ABSTRACT FROM AUTHOR]

Background: Accumulating evidence has shown that protein-rich milk drinks can rapidly improve cognitive performance. However, the optimum doses of milk protein that are needed to improve cognitive function remain to be investigated. Objective: This study aimed to determine whether acidified milk drinks with 10-g and 15-g milk protein have acute benefits on key cognitive functions in healthy young adults. Design: In this double-blinded randomized control trial, 66 young adults were randomly assigned to one of three groups (0-g, 10-g, and 15-g milk protein groups). Key cognitive functions (processing speed, inhibition, shifting, updating, and working memory capacity) were assessed before and 15 and 60 min after the drink intake. Results: We found that the shifting performance improved at 15 min after intake of the acidified 10-g and 15-g milk protein drinks compared to intake of the 0-g milk protein drink, and this acute effect of the acidified 15-g milk protein drink lasted for 60 min. In addition, updating performance improved at 60 min after intake of the acidified 10-g and 15-g milk protein drinks compared to intake of the 0-g milk protein drink. Conclusion: Our findings suggest that the acidified 10-g and 15-g milk protein drinks have an acute benefit on shifting and updating performance in healthy young adults. [ABSTRACT FROM AUTHOR]

The experiment was to investigate the effect of the interaction between acetic acid and methionine (Met) on expression and mechanism of milk protein synthesis-related genes and proteins in cow mammary epithelial cells (BMECs). The experiment adopts a 2×6 two-factor completely randomized experimental design. The first factor was the concentration of acetic acid, which were set six levels of 0, 4, 6, 8, 10 and 12 mmol/L. The second factor was the Met concentration, which were set to two levels of 0.13 and 0.52 mmol/L. The third-generation BMECs were randomly divided into 12 treatment groups, with six replicates in each group, and each index was measured after 48 h of culture according to experimental requirements. The results showed that when the Met concentration was 0.13 mmol/L or 0.52 mmol/L, with the increase of acetic acid concentration, the expressions of CSN3、JACK2、STAT5 in BMECs were all up-regulated, and CSN1S1 was significantly decreased. When acetic acid was 8, 10, 12 mmol/L, the expression of CSN3、JACK2、STAT5、 CSN1S1 was significantly increased when acetic acid was 8 mmol/L, the expressions of CSN3 and JACK2/STAT5 were significantly increased, and when acetic acid was 0, the expression of CSN1S1 was significantly increased, when the acetate concentration was 6, 8, 10, 12 mmol/L, the expressions of mTOR and 4EBP1 were significantly increased. When the Met concentration was 0.13 mmol/L or 0.52 mmol/L, the gene expression of JACK2/STAT5 signaling pathway, the expression of mTOR and its downstream related factors increased with the increase of acetate concentration. Phosphorylation levels first increased and then decreased. The experiment indicates that the interaction between Met and acetic acid has a significant effect on the synthesis of milk protein in BMECs, and the combination of Met concentration of 0.52 mmol/L and acetic acid concentration of 6 mmol/L has better promotion effect. [ABSTRACT FROM AUTHOR]

Copyright of Stocarstvo is the property of Croatian Society of Agronomists and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Chinese Institute of Food Science & Technology / Zhongguo Shipin Xuebao is the property of Journal of Chinese Institute of Food Science & Technology Periodical Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aflatoxin M1 (AFM1) is a metabolite of carcinogenic aflatoxin B1 (AFB1) and appears in milk of dairy animals on ingestion of feed contaminated with AFB1. It has been reported to have affinity towards milk proteins, the exact mechanism of which is still unknown. In the present study, ATR-FTIR coupled with chemometrics is utilized to understand AFM1 interaction with milk proteins. The second order derivative spectra of the spectral window 1700–1600 cm−1 confirms the affinity of AFM1 towards milk proteins. The results of principal component analysis suggested that spectral window of 1700–1600 cm−1 is informative and provides an indication of the conformational changes brought by AFM1 in the secondary structure of milk proteins. [ABSTRACT FROM AUTHOR]

Background: Goat milk production has been increasing in northern Mexico; however, there is little information available about its quality. Objective: To compare goat milk quality during three seasons among creole goats in a traditional grazing system and stabled Saanen and French-Alpine goats. Methods: An experiment was performed in a completely randomized nested design with seasonality factor (fixed effects) with three levels (rain, transition, and drought) and breed factor (fixed effect with three levels (Creole, Saanen and French-Alpine)) nested within the season-of-the-year factor. Fifteen goats were randomly selected: five Creole in the extensive grazing system, five stabled Saanen, and five stabled French-Alpine. The factors assessed in milk were fat content, non-fat solids, protein, lactose, salts, density, freezing point, conductivity, and pH (using a Lactoscan® device). Results: With respect to season for all the breeds: fat, non-fat solids, protein, lactose, and salt contents were higher (p≤0.05) for goats sampled in the rainy season, followed by drought and transition seasons, respectively. The variables related to milk quality by breed and season showed that milk fat content of creole goats was greater (p≤0.05) in the drought season; salt and non-fat content (p≤0.05) in the three seasons of the year; density and protein increased (p≤0.05) in the transition and rainy seasons, while lactose was greater (p≤0.05) in drought and rainy seasons; protein was greater (p≤0.05) in transition and rainy seasons; and the freezing point was lower (p≤0.05) in the transition season. Regarding conductivity, French-Alpine milk was greater (p≤0.05) in the drought season. Conclusion: Season of the year significantly affects milk quality, with increased quality during the rainy season in creole grazing goats.

Milk production determines health status and optimal growth of suckling neonates. Recent studies revealed that the secretion of leucine into sow milk from the mammary gland is significantly lower than the amount taken up by the mammary gland from the blood, suggesting the potential and fundamental role in udder metabolism. However, little is known about the underlying mechanism. In this study, porcine mammary epithelial cells (PMECs) were employed to investigate the effects of leucine on protein synthesis and mammalian target of rapamycin (mTOR) signalling. Results showed that leucine supplementation significantly increased the proliferation of PMECs in a dose-dependent manner from 0 to 1 mmol/l. Secretions of four casein subunits were significantly increased by addition of leucine. The phosphorylation of proteins related to mTOR signalling, including mTOR, eukaryotic translation initiation factor 4E-binding protein, and p70 ribosomal protein S6 kinase, were accordingly upregulated by leucine supplementation. Casein secretion was not affected by leucine treatment when mTOR signalling was inhibited by rapamycin. This suggests that leucine stimulates protein synthesis through the mTOR signalling pathway. These findings facilitate the utilization of dietary leucine supplementation to improve milk production in lactating sows.

ABSTRACT: Protein disulfide isomerase family A member 3 (PDIA3) is a multifunctional protein, and it plays a vital role in modulating various cell biological functions under physiological and pathological conditions. Our previous study on Mediterranean buffalo demonstrated that PDIA3 is a potential candidate gene associated with milk yield based on genome-wide association study analysis. However, the genetic effects of the PDIA3 gene on milk performance in dairy cattle and the corresponding mechanism have not been documented. This study aims to explore the genetic effects of PDIA3 polymorphisms on milk production traits in 362 Chinese Holstein cattle. The results showed that 4 SNPs were identified from the 5′ untranslated region of the PDIA3 gene in the studied population, of which 2 SNPs (g.-1713 C>T and g.-934 G>A) were confirmed to be significantly associated with milk protein percentage, whereas g.-434 C>T was significantly associated with milk fat percentage. Notably, linkage disequilibrium analysis indicated that 3 SNPs (g.-1713 C>T, g.-934 G>A, and g.-695 A>C) formed one haplotype block, which was found to be significantly associated with milk protein percentage. The luciferase assay demonstrated that allele C of g.-434 C>T exhibited a higher promotor activity compared with allele T, suggesting that g.-434 C>T might be a potential functional mutation affecting PDIA3 expression. Furthermore, overexpression of the PDIA3 gene was found to induce higher levels of triglyceride and BODIPY fluorescence intensity. In addition, PDIA3 overexpression was also found to positively regulate the synthesis and secretion of α-casein, β-casein, and κ-casein, whereas knockdown of this gene showed the opposite effects. In summary, our findings revealed significant genetic effects of PDIA3 on milk composition traits, and the identified SNP and the haplotype block might be used as genetic markers for dairy cow selected breeding.

ABSTRACT: Feed evaluation models (FEM) are a core part in dairy cow feeding. As these models are developed using different biological and mathematical approaches mainly tested in a research context, their abilities to predict production in commercial farms need to be validated, even more so when they are used outside the context of their development. Four FEM—National Research Council, 2001 (NRC_2001); Cornell Net Carbohydrate and Protein System, 2015 (CNCPS); NorFor, 2011; and INRA, 2018 (INRA_2018)—were evaluated on their abilities to predict daily milk protein yield (MPY) of 541 cows from 23 dairy herds in the province of Québec, Canada. The effects of cow and diet characteristics were tested on the residuals of MPY. Sensitivity and uncertainty analyses were then performed to evaluate the influence of the uncertainty of the main characteristics of cows and feed ingredients measured on the farm and used in the 4 FEM on the predictions of metabolizable protein (MP) supply and MPY. The 4 models had acceptable predictions of MPY, with concordance correlation coefficients (CCC) ranging from 0.75 to 0.82 and total bias ranging from 12.8% to 19.3% of the observed mean. The Scandinavian model NorFor had the best predictions with a CCC of 0.82, whereas the 3 other models had similar CCC at 0.75 to 0.76. The INRA_2018 and NRC_2001 models presented strong central tendency biases. Removing herd effect put the 4 FEM at the same level of performance, with 11.9 to 12.4% error. Analyzing model behavior within a herd seems to partly negate the effect of using predicted dry matter intake (DMI) in the comparison of models. Diet energy density, days in milk, and MPY estimated breeding value were related to the residual in the 4 models, and Lys and Met (as percent of MP) only in NRC_2001 and NorFor. This suggests that inclusion of these factors in these models would improve MPY predictions. From the sensitivity analysis, for the 4 FEM, DMI and factors affecting its prediction had the greatest influence on the predictions of MP supply and MPY. Of the feed ingredients, forage composition had the greatest effect on these predictions, including a strong effect of legume proportion with NorFor. Diet acid detergent fiber concentration had a very strong effect on MP supply and MPY predictions only in INRA_2018, because of its effect on organic matter digestibility estimation. The range of predictions of MP supply and MPY when combining all these potential uncertainties varied depending on the models. The INRA_2018 model presented the lowest standard deviation (SD) and NorFor the highest SD for the predictions of both MP supply and MPY. Overall, despite the fact that FEM were developed in a research context, their use in a commercial context yields acceptable predictions, with NorFor yielding the best predictions overall, although within-herd responses varied similarly for the 4 tested models.

This study aims to determine the effects of D-methionine (D-Met) isomer and the methionine precursor 2-hydroxy-4-methylthiobutanoic acid i (HMBi) supplementation on milk protein synthesis on immortalized bovine mammary epithelial cell (MAC-T). MAC-T cells were seeded using 10-cm dishes and cultured in Dulbecco’s modified Eagle’s medium/F12 (DMEM/F12) basic medium. The basic medium of DMEM/F12 was replaced with the lactogenic DMEM/F12 differentiation medium when 90% of MAC-T cells reached confluency. The best dosage at 0.6 mM of D-Met and HMBi and incubation time at 72 h were used uniformly for all treatments. Each treatment was replicated six times wherein treatments were randomly assigned in a 6-well plate. Cell, medium, and total protein were determined using a bicinchoninic acid protein assay kit. Genes, proteomics and metabolomics analyses were also done to determine the mechanism of the milk protein synthesis pathway. Data were analyzed by two-way analysis of variance (ANOVA) with supplement type and plate as fixed effects. The least significant difference test was used to evaluate the differences among treatments. The HMBi treatment group had the highest beta-casein and S6 kinase beta-1 (S6K1) mRNA gene expression levels. HMBi and D-Met treatments have higher gene expressions compared to the control group. In terms of medium protein content, HMBi had a higher medium protein quantity than the control although not significantly different from the D-Met group. HMBi supplementation stimulated the production of eukaryotic translation initiation factor 3 subunit protein essential for protein translation initiation resulting in higher medium protein synthesis in the HMBi group than in the control group. The protein pathway analysis results showed that the D-Met group stimulated fructose–galactose metabolism, glycolysis pathway, phosphoinositide 3 kinase, and pyruvate metabolism. The HMBi group stimulated the pentose phosphate and glycolysis pathways. Metabolite analysis revealed that the D-Met treatment group increased seven metabolites and decreased uridine monophosphate (UMP) production. HMBi supplementation increased the production of three metabolites and decreased UMP and N-acetyl-L-glutamate production. Taken together, D-Met and HMBi supplementation are effective in stimulating milk protein synthesis in MAC-T cells by genes, proteins, and metabolites stimulation linked to milk protein synthesis.

It is known that a balanced diet and the intake of specialized foods that combine various types of proteins play a key role in expanding the adaptive potential of athletes and affect the effectiveness of the training process. In recent decades, various biomedical and technological strategies have been implemented in the development of specialized food products, including those for the nutrition of athletes. Proteins of milk and whey occupy an important place among the functional ingredients. Despite the fact that the average per capita consumption of protein in the structure of the diet in the Russian Federation over the past few years has been at a satisfactory level (in 2019 — 80.4 g/day, in 2020 — 81.4 g/day), for athletes with high body weight and extremely high energy consumption (4000 kcal/day and above), these values will be insufficient. In connection with this, special attention should be paid to various protein fractions in the development of SPP at a consumption level of at least 1.2 g/kg of the athlete’s body weight daily to ensure plastic and other functions in the body, physical performance and endurance.

Abstract Background Gastrointestinal helminthiasis poses economic impacts on the dairy sector by reducing milk production. This study aimed at estimating the prevalence of gastrointestinal helminthiasis, the burden of helminths, and appraising potential factors associated with the prevalence in lactating cows. The study was also designed to elucidate the effects of anthelmintic treatment on milk yield, milk fat, and protein content in the Kucha district. Methods A cross-sectional and field clinical trial study designs were used. Standard parasitological techniques (floatation and sedimentation) were employed to detect cows’ infection status. McMaster and Stoll’s egg counting methods were used to estimate helminths' burden. All putative factors that might have been linked with infection were recorded by field observations and farmers' interviews. Sixty cows tested positive for the parasitic infection in the cross-sectional study design were randomly assigned into one of the two groups (dewormed Vs control). Milk yield, milk fat and protein contents were recorded in both groups on day zero and then on weekly basis. Descriptive statistics, binary logistic regression, and repeated measure ANOVA were used to analyze the data. Results Overall, of 422 examined cows, 150 (35.5%, 95% CI; 30.9-40.3%) were infected with at least one of the gastrointestinal helminth parasites. Strongyle nematode was the predominant type accounting for 52% of the total record. Analysis of fecal egg count (FEC) in infected cows depicts the highest record of Parampistomum egg, accounting 457.14 ± 275.45 Egg per gram (EPG) of feces. The prevalence of gastrointestinal helminthiasis in cow that had an average body condition score of 1.7 was over two fold higher (OR = 2.19, 95% CI = 1.17–4.17, P = 0.016) than in cows with 6.3 body condition score. A significant improvement in milk yield, milk fat, and milk protein was observed in dewormed cows over 28 days period. Conclusion Gastrointestinal helminthiasis is threatening the welfare of lactating cows in Kucha, Ethiopia given its negative association with the body condition score. Gastrointestinal helminths are responsible for the reduction of milk yield and loss of milk fat and protein. However, an improvement in milk yield, milk fat, and milk protein after deworming using Tetrox® (Tetramisole and Oxyclozanide combination), a new drug to the area/ a drug used by relatively few farmers in the study area, proves the effectiveness of strategic deworming.

The subject for the research was Phytoadditive containing extracts from herbs: Rhaponticum carthamoides, Serratula coronata, Filipendula ulmaria. There has been studied the effect of Phytoadditive on biochemical parameters of blood (total protein, albumins, aminotransferases, urea, total cholesterol, reserve alkalinity, calcium), indicators of milk fat, protein and average daily milk yield of lactating cows at the age of 3 years, which were divided into experimental (Phytoadditive + basic diet) and control (basic diet only) groups of 10 animals per group. Phytoadditive in powder form was administered individually to the diet of animals of the experimental group daily, once at a dose of 10 grams per head per day during 90 days. Analysis of Phytoadditive for the presence of biologically active substances showed that the major compounds in it are ecdysteroids (mainly hydroxyecdysone) and flavonoids (rutin) in a total concentration of 13.5 g/kg. At the end of the experiment in cows of the experimental group, in comparison with the initial indicators, significantly (p < 0.05) increased the amount of albumin by 16.7 % (up to 45.3±2.4 g/l), calcium by 21.7 % (2.3±0.01-2.8±0.02 mmol/l). Other studied markers of the biochemical status did not change significantly (p> 0.05) and after the final blood test they were: aminotransferases (AST − 30.1±1.2 U/l, ALT − 35.0±2.8 U/l), urea (5.9±0.1 mmol / l), reserve alkalinity (20.2±2.6 vol.% CO2), cholesterol (2.8±0.1 mmol/l). All studied blood parameters did not go beyond the reference values throughout the experiment, which indicated the absence of any negative properties of Phytoadditive. At the end of the experiment, the milk indicators of cows in the experimental group had the following values: milk yield (19±0.2 kg), fat (4.3±0.4 %), protein (3.3±0.1 %), which exceeded the result in control by 5.5 %; 0.1 and 0.2 %, and in comparison with the beginning of the experiment by 18.7 %, 0.6 and 0.2 %, respectively. Thus, as the result of use of Phytoadditives in cows during lactation, a positive trend was noted in terms of its effect on milk yield, milk quality and the absence of any negative effect on the studied blood parameters.

The small amplitude oscillatory shear (SAOS) rheological properties of complex coacervate of milk proteins with high (HMC), medium (MMC), and low (LMC) molecular weight chitosan in the optimal ratios of milk proteins to chitosan (15:1, 10:1, and 5:1, respectively) were measured. In addition, the morphological (SEM), structural (XRD), and thermal (DSC) properties of the complex coacervates were investigated in comparison with the milk protein concentrate. Complex coacervates showed the shear-thinning behavior due to a linear decrease of complex viscosity with increasing frequency. Furthermore, the highest complex modulus and the more compact structure under optimal conditions, in terms of the ratio of protein to chitosan and pH, revealed strong electrostatic bonding between proteins and chitosan. All coacervates showed a G′ > G″ (Tanδ<1), indicating the formation of an interconnected gel-like structure that was described by the power law model. The maximum fracture stress was obtained at optimum conditions (R = 15:1, pH =6.7 for HMC; R = 10:1, pH =5.5 for MMC and R = 5:1, pH =4.6 for LMC), indicating the highest intermolecular interaction between milk proteins and chitosan. The coacervates had a completely amorphous structure similar to MPC, and according to DSC results, the ionic bonds between milk proteins and chitosan were not destroyed up to 300 °C. Coacervation leads to purified milk proteins at a low cost. In addition, the coacervates can be used for the encapsulation of heat-sensitive compounds, and also as a stabilizer to improve the texture of food. [ABSTRACT FROM AUTHOR]

[Display omitted] • Gastric digestion of differently heated milk products was studied in a human trial. • Gastric coagulation did not differ between the milk products. • More extensive heat treatment resulted in faster gastric emptying. • MT MRI gives a semi-quantitative in vivo view of milk digestion. Gastric milk protein coagulation has been extensively studied using in vitro and animal models. Yet, verifying these results in humans remains essential. In this study, we assessed the feasibility of using MT MRI for monitoring milk protein coagulation in vivo in humans. Twelve adults underwent MRI scans before and after ingesting 300 g of milk with low- or high-protein denaturation (LPD or HPD, respectively). We assessed coagulation and gastric emptying dynamics by deriving the MT ratio (MTR) , total gastric content (TGC), semi-solid, and liquid volumes. The MTR values increased during digestion for both milk products, indicating an increase in the degree of coagulation. Prolonged heating of milk did not affect the MTR (MD = 16 %, 95 % CI [10–21], p = 0.15), but resulted in higher TGC volumes (MD 40.3 mL, 95 % CI [25.5–55.1], p = 0.044), indicating slower gastric emptying. We thus showed that by combining MT with conventional anatomical MRI both milk protein coagulation and gastric emptying dynamics, and thereby the impact of heating on gastric milk digestion, can be assessed in vivo in humans. Our work underpins the feasibility of using MRI as a non-invasive imaging tool for studying the effects of food processing and composition on gastric digestion. [ABSTRACT FROM AUTHOR]

• Hypoxia stress inhibits the synthesis of milk protein and milk fat in MAC-T cells. • Hypoxia stress inhibits the AKT/mTOR signaling pathway in MAC-T cells. • L-leucine supplementation significantly promotes the synthesis of milk protein and fat under hypoxic conditions. • L-leucine promotes milk protein and fat synthesis through the AKT/mTOR signaling pathway under hypoxic conditions. Hypoxia stress has been demonstrated to impede animal embryonic development, spermatogenesis, and lactation, leading to decreased animal production performance. However, the impact of hypoxia-induced activation of hypoxia inducible factor-1 (HIF-1) signaling on milk protein and fat synthesis remains unclear. L-leucine, a branched-chain amino acid, is known to modulate milk protein and fat synthesis. Therefore, our study aimed to evaluate the effect of L-leucine on milk protein and fat synthesis under hypoxic conditions and shed light on the molecular mechanism using an in vitro model. The results indicated that hypoxia treatment significantly decreased the synthesis of α-casein and β-casein, as well as inhibited factors related to milk fat synthesis in bovine mammary epithelial cells (MAC-T). Additionally, hypoxia stress suppressed the activities of the mammalian target of rapamycin (mTOR) and protein kinase B (AKT). Interfering with HIF-1α significantly reversed the expression of AKT, mTOR and factors related to milk synthesis. Importantly, supplementation with L-leucine activated AKT/mTOR signaling, thereby enhancing milk protein and fat synthesis in MAC-T cells to some extent. In conclusion, these findings suggest that HIF-1 signaling plays an important role in milk synthesis and that L-leucine may stimulate the synthesis of milk protein and fat by activating the AKT/mTOR signaling pathway under hypoxic conditions, making it a potential additive for promoting milk synthesis inhibited by hypoxia. [ABSTRACT FROM AUTHOR]

Our previous study suggested that bound phenolic acids of rice bran were converted into free phenolic acids during fermentation and these free phenolic acids improved the yogurt stability. Thus, this work investigated the effect of adding ferulic acid, the major phenolic acid of rice bran, on the yogurt stability. It was observed that the syneresis of yogurt was reduced by adding 100 μg/mL ferulic acid before fermentation, which suggested that ferulic acid increased the yogurt stability. Accordingly, adding ferulic acid made the yogurt gel more compact. However, 100 μg/mL ferulic acid had no significant impact on the pH, viscosity, and viscoelasticity of yogurt. Thus, the interaction between ferulic acid and milk protein was investigated. It was observed that ferulic acid interacted with milk protein through the hydrogen bond and van der Waals force. Therefore, it was speculated that ferulic acid interacted with milk protein molecules and induced the more compact structure of yogurt, thus improving the yogurt stability. However, adding ferulic acid after fermentation had no significant impact on the yogurt stability, because the gelation of milk protein caused by fermentation hindered the interaction between ferulic acid and milk protein. [ABSTRACT FROM AUTHOR]

This study fills a specific knowledge gap by comprehensively investigating the intestinal digestive dynamics and transport kinetics of pasteurized milk proteins during cold storage, utilizing dynamic in vitro digestion models, human colorectal adenocarcinoma cell line (Caco-2) transport simulations, peptideomics and amino acid analysis. The content of free amino acids during intestinal digestion and their transport capacity (excluding lysine) were highest in pasteurized milk stored for 7 days (PAST-D7), intermediate in pasteurized milk stored for 0 days (PAST-D0) and lowest in raw milk (RM). Conversely, the quantity and intensity of bioactive peptides during digestion decreased with pasteurization and storage. Additionally, pasteurization and storage reduced the intensity of bioactive peptides transported through Caco-2 cells and the types and intensity of potential allergenic peptides. These findings indicate that while pasteurization and storage may diminish some physiological benefits of milk, they may also enhance protein bioavailability and reduce allergenicity. • The levels of FAAs post-digestion and their transport capacity (excluding lysine) were: PAST-D7>PAST-D0>RM. • The quantity and intensity of bioactive peptides post-digestion and post-transportation were: RM > PAST-D0>PAST-D7. • Pasteurization and storage reduced the types and intensity of probable allergens post-transportation. [ABSTRACT FROM AUTHOR]

In this study, dairy protein (whey protein isolate, WPI) and dairy ingredients (sodium hyaluronate, SH) were selected as candidates for probiotic encapsulation, directly useable as starters for dairy products. The effects of different weight ratios of WPI and SH (1:0, 3:1, 1:1, 1:3, and 0:1) on the encapsulation of two probiotic strains were investigated. Characteristic properties and survival ability under low pH, bile salts, simulated gastrointestinal conditions, high temperatures, and freezing temperatures were determined. The highest encapsulation rates of Lb. sakei and Lb. rhamnosus were 98.48% and 86.59%, respectively. Differential Scanning Calorimetry (DSC) and Fourier Transform Infrared (FTIR) spectroscopy results showed that the interaction between WPI and SH via hydrophobic and hydrogen bonding increased thermal stability. Compared to free bacterial cells, the survival rate significantly increased at pH 2.0. Under simulated gastrointestinal conditions, Lb. sakei J15 was achieved the best protection with a with a 45.39% survival rate at a WPI:SH ratio of 3:1, whereas Lb. rhamnosus S8 also had a survival rate of 62.96% at the same ratio. At the highest experimental temperature (70 °C), Lb. sakei J15 had the highest survival rate of 31.95% at a WPI:SH ratio of 1:3, whereas Lb. rhamnosus S8 exhibited a 20.55% survival rate at the WPI:SH ratio of 3:1. Although different ratios exhibited varying properties, a WPI:SH ratio of 3:1 was the most effective for maintaining bacterial viability under external environmental conditions. These findings demonstrate a new probiotic delivery system and provide insights into the underlying mechanisms of complex formation and bacterial survival. [Display omitted] • Formation of a new food-grade probiotic delivery material using WPI and SH. • Properties of encapsulated probiotics using different ratio of WPI and SH were investigated. • Survival ability of encapsulated probiotics under external environment conditions were determined. • WPI-SH complex effectively protect probiotics and enrich probiotic functions. [ABSTRACT FROM AUTHOR]

The aim of the study was to investigate the phenotypic correlations and the regression curve among the main phenotypic parameters of milk yield in a herd of 63 primiparous Romanian Black Spotted breed dairy cows from SC Dorin&Sanda SRL, Petreşti-Alba farm. The phenotypic correlations for milk, fat and protein yields were estimated. A positive and very high correlation of +0.99 was registered between milk and fat yields. Between milk and protein yields the correlation was also high and positive, +0.99, with a very close value of the correlation between fat and protein yields, +0.98. Results obtained show that among the main parameters of milk yield there are very strong phenotypic correlations.

The current food system suffers from the inefficient use of resources, including the generation of side streams of low economic value that still contain nutritional components. One potential approach to reach a more sustainable food system is to reintroduce such side streams into a circular value chain and valorise them in novel food products, preferably in an unrefined or minimally refined manner. Blending side streams from different industries might be a suitable way to improve the nutritional value of the final matrix. In this study, sunflower seed press cake and cheese whey were combined to obtain matrices containing valuable proteins, structuring polysaccharides, as well as lactose and minerals facilitating fermentation with three different co-cultures of lactic acid bacteria and yeasts. Fermentation for 48 h at 26 °C decreased the pH from ~6.3 to ~4.7 and enhanced the storage stability of the blends with no effect on their rheological properties and microstructure. This research demonstrates the potential of fermentation as a mean to stabilise side stream blends while only minimally affecting their physical appearance.

Milk yield and composition in cattle are typical quantitative traitswhich are influenced by environmental factors and allelic variations. K-casein is a protein expressed in milk and, due to is polymorphism, may serve as a molecular marker for yield, composition and technological properties of milk. The objective of this study was to compare the relation between the genetic marker CSN3 (k-casein) and the observed milk traits in selected cattle groups. In our study we analyzed the milk traits of 32 Romanian Brown dairy cows and 54 Romanian Simmental dairy cows. The experiments described in this paper show clear evidence that -CSN3 genotype is involved in milk protein enrichment. The CSN3 gene of BB genotype showed a grate influence on protein yield. The relation between CSN3 genotype and milk protein was found to be significant in both cattle breed.

Abstract Background The mammary gland is responsible for milk production and secretion, which is critical for neonatal health during lactation. Lactation efficiency is largely affected by energy status with unclear mechanism. Results In the current study, we found that synthesis of milk fat and protein was significantly inhibited under energy-deficient conditions, which is accompanied with AMP-activated protein kinase (AMPK) activation. Modulating the AMPK signaling pathway directly or indirectly affects the synthesis of milk fat and protein. Besides mammalian target of rapamycin complex 1 (mTORC1) signaling in the regulation of milk synthesis, we discovered that AMPK mainly regulates the synthesis of milk protein through prolactin signaling. Mechanistically, AMPK triggers the ubiquitination of prolactin receptor (PrlR) through regulating the activity of β-transducin repeat-containing protein (β-TrCP, an E3 ligase). Subsequently, PrlR is degraded by the endocytosis process of lysosomes, which further attenuates prolactin signaling. In addition, our results revealed that AMPK activation inhibits milk fat synthesis through decreasing and accelerating de novo synthesis and β-oxidation of fatty acids, respectively. To be precise, AMPK activation inhibits rate limiting enzymes and transcriptional regulatory factors involved in de novo fatty acid synthesis and decreases the acetylation process of peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) to strengthen the oxidation of fatty acids. Conclusions Taken together, AMPK regulates the synthesis of milk not only depends on canonical mTORC1 signaling and key rate-limiting enzymes, but also through manipulating the degradation of PrlR and the acetylation of PGC-1α. Video Abstract

Milk protein is an important component in milk and dairy products, and its content and composition are important factors influencing the functionality of milk such as nutrition and immunity. Protein components in milk are complex, and the content of different components varies greatly. With the development of functional properties of milk protein, it is of great significance and value to determine the content of milk protein components in a faster and more accurate way. Currently, enzyme-linked immunosorbent assay (ELISA), capillary electrophoresis (CE), high performance liquid chromatography (HPLC) and high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) are the main methods used to determine protein components in milk. In this article, the measurement principle, applicability, and the characteristics of these methods are reviewed, which could provide reliable technical reference for accurate measurement and establishment of a novel method in milk protein evaluation, while this could also be a theoretical support for dairy nutrition research, development of dairy products and infant formula optimization.

In this work, the binding interaction of fluvastatin (FLU) and pit-avastatin (PIT) with bovine β-casein (β-CN) were performed under physiological conditions (pH 7.2) by fluorescence emission spectroscopy, synchronous fluorescence spectroscopy, Fourier transform infrared spectroscopy (FTIR) and molecular docking methods. Due to the formation of FLU-β-CN and PIT-β-CN complexes, the intrinsic fluorescence of β-CN was quenched. The number of bound FLU and PIT per protein molecule (n) were about 1, also the binding constant of FLU-β-CN and PIT-β-CN complexes were 7.96×104 and 3.44×104 M-1 at 298 K, respectively. This result suggests that the binding affinity of FLU to β-CN was higher than that for PIT. Molecular modelling showed different binding sites for FLU and PIT on β-CN. All these experimental results suggest that β-CN can be used as a carrier protein which delivers FLU and PIT based drugs to target molecules.

ABSTRACT: A study was conducted to investigate the inclusion effects of sugar beet pulp and rice straw mixture silage with inoculation (BRMS), in place of whole-plant corn silage (CS), on the dry matter intake, total-tract nutrient digestibility, plasma metabolites, rumen fermentation, and lactation performance in high-production dairy cows. Sixteen multiparous Holstein cows (body weight, 622 ± 35 kg; days in milk, 90 ± 11 d; mean ± standard deviation) were used in our experiments; the experiments were based on a repeated 4 × 4 Latin square design for 21 d, and each experimental period consisted of 14 d of adaptation, followed by 7 d of data collection. The 4 dietary treatments used were (dry matter basis): (1) 0% BRMS and 28.6% CS (0BRMS); (2) 4.3% BRMS and 24.3% CS (15BRMS); (3) 8.60% BRMS and 20.0% CS (30BRMS); and (4) 12.9% BRMS and 15.7% CS (45BRMS). The increasing inclusion of dietary BRMS was observed to linearly increase the total volatile fatty acids and the propionate concentration. The dry matter intake and digestibility values of neutral detergent fiber and acid detergent fiber increased linearly as the percentage of BRMS increased up to 45%. Milk yield linearly increased with the increase in the content of BRMS (39.0, 39.8, 40.9, and 40.3 kg/d for 0BRMS, 15BRMS, 30BRMS, and 45BRMS, respectively). The increasing inclusion of dietary BRMS induced a decrease in the ammonia nitrogen and milk urea nitrogen concentration, leading to a linear increase in milk protein production (1.15, 1.26, 1.35, and 1.27 kg/d for 0BRMS, 15BRMS, 30BRMS, and 45BRMS, respectively). In conclusion, the diets with the replacement of CS with BRMS up to 45% were beneficial to the production performance of high-production dairy cows, indicating that this method may be an appropriate use of sugar beet pulp and rice straw.

Casein is one of the milk proteins which have the unique characteristic, it is called assembly. Assembly is casein can interact with casein or others to form micelle casein nanoparticle. The nano size of casein can accelerate the process of absorption into the body, making it suitable as a delivery system of nutraceutical food. It can happen with the appropriate temperature. According to the statement, this research aims to determine the best temperature for the reassembling process of casein with phenolic at different temperature (40°C, 50°C, and 60°C) with four replications.

Milk protein is a key quality indicator of milk, so elucidating its synthesis mechanism has been the focus of research in recent years. Studies have shown that both miRNAs and mRNA genes play important roles in the regulation of milk protein synthesis. In this study, a total of 7 and 4073 differentially expressed miRNA and mRNA genes were identified between early and peak lactation, respectively. Overexpression and knockdown experiments of parathyroid hormone like hormone gene (PTHLH) gene showed that it can promote milk protein synthesis in buffalo mammary epithelial cells (BuMECs) through mammalian target of rapamycin (mTOR) and janus kinase 2/signal transducer and activator of transcription 5 (JAK2–STAT5) signaling pathways, and the experiments treated with miR-190a mimic or inhibitor showed that miR-190a inhibited the expression of PTHLH gene. In addition, miR-190a inhibited milk protein synthesis by targeting PTHLH through mTOR and JAK2–STAT5 signaling pathways in BuMECs. Collectively, these findings reveal a novel miR-190a–PTHLH pathway that has a significant role in regulating milk protein synthesis.

Systematic modeling of the enzymatic hydrolysis of milk proteins is needed to assist the study and production of partially hydrolyzed milk. The enzymatic hydrolysis of milk proteins was characterized and evaluated as a function of the temperature and protease concentration using Alcalase, Neutrase and Protamex. Modeling was based on the combination of two empirical models formed by a logarithmic and a polynomial equation to correlate the kinetic constants and the operating conditions. The logarithmic equation fitted with high accuracy to the experimental hydrolysis curves with the three proteases (R2 > 0.99). The kinetic constants were correlated with the operating conditions (R2 > 0.97) using polynomial equations. The temperature and protease concentration significantly affected the initial rate of hydrolysis, i.e., the kinetic constant a, while the kinetic constant b was not significantly affected. The values for the kinetic constant a were predicted according to the operating conditions and they were strongly correlated with the experimental data (R2 = 0.95). The model allowed for a high-quality prediction of the hydrolysis curves of milk proteins. This modeling tool can be used in future research to test the correlation between the degree of hydrolysis and the functional properties of milk hydrolysates. [ABSTRACT FROM AUTHOR]

The milk casein genes in goats, are highly polymorphic genes with numerous synonymous and non-synonymous mutations. So far, 20 protein variants have been reported in goats for alpha-S1-casein, eight for beta-casein, 14 for alpha-S2-casein, and 24 for kappa-casein. This review provides a comprehensive overview on identified milk casein protein variants in goat and non-coding DNA sequence variants with some affecting the expression of the casein genes. The high frequency of some casein protein variants in different goat breeds and geographical regions might reflect specific breeding goals with respect to milk processing characteristics, properties for human nutrition and health, or adaptation to the environment. Because protein names, alongside the discovery of protein variants, go through a historical process, we linked old protein names with new ones that reveal more genetic variability. The haplotypes across the cluster of the four genetically linked casein genes are recommended as a valuable genetic tool for discrimination between breeds, managing genetic diversity within and between goat populations, and breeding strategies. The enormous variation in the casein proteins and genes is crucial for producing milk and dairy products with different properties for human health and nutrition, and for genetic improvement depending on local breeding goals. [ABSTRACT FROM AUTHOR]

The characterization of miRNAs from sheep milk and their effect on milk yield and composition in sheep are remain unclear. Therefore, the aim of this study was to determine the expression pattern of several important miRNAs, which are associated with lactation in the sheep milk between high and low lactating-yield ewe groups. In addition to experimentally obtained miRNA expression results, the miRNA target genes were determined by bioinformatics analysis to identify biological pathways involved. miRNAs found to differ significantly in the expression level between the groups were oar-miR-181a, oar-miR-23a, oar-miR-27a, oar-miR-16b and oar-miR-374. Also, oar-miR-27a was shown negative correlation with milk protein and lactose contents while oar-miR-16b was shown negative correlation with milk yield in the high milk yield group. The highest connected hub genes for miR-27a target genes were determined as MAPK14 and PPARG. Also, six genes (HSPA4L, DNAJA2, ATP6V1B2, PPP2R1A, PPP2R1B, and PRKAR2A) were detected as hub genes for miR-16b. In this study, the relationship between expression profiles of several important miRNAs in sheep milk and milk yield and milk composition were investigated for the first time in high and low lactating yield groups. [ABSTRACT FROM AUTHOR]

Context: Dairy farming in Brazil is characterised by heterogeneity in production techniques, herds and kinds of producers; nonetheless, it has expanded in recent years. The data available in the scientific literature regarding breeds used in the system are inconsistent and may not represent the current genetic, productive and reproductive profile of Brazilian herds. Aim: This study was developed to understand differences between animals used in experiments and those in breed control assessments. We aimed to evaluate data of Holstein, Gyr, Guzerat, Jersey, Sindhi, Brown Swiss, Holstein × Gyr and Holstein × Guzerat cattle on the traits 305-day milk yield, fat and protein contents, lactation length, age at first calving, and calving interval by comparing research literature and national official control records. Methods: National breeders' associations (NBAs) for each breed or cross were asked to send their official control from 2019 for comparison with 15 years of published data that we retrieved from the literature. Key results: Holsteins showed the closest mean for milk yield between literature and NBA data. In Holstein × Gyr crosses, increasing the proportion of Gyr genes decreased milk yield. Jersey data showed the greatest variance between the literature and NBA. For Brown Swiss milk fat, literature values were 12.7% above NBA values. Holsteins had the longest lactation (305 days), and 5/8 Holstein × Gyr the shortest (262 days). For age at first calving, Jerseys were the youngest (26.3 months) and Guzerats the oldest (45.7 months). Jersey cows showed the shortest (best) mean calving interval (12 months), and Sindhi the longest (17 months). NBA data were not available for comparison for some traits in some breeds/crosses. Conclusions: Holstein was the most productive breed. Holstein × Gyr crosses, because of adaptation and management, were able to express their productive and reproductive potentials. There was variance between literature and NBA data. Implications: We expected that the literature data would somewhat represent the NBA data; however, for most traits, NBA data do not coincide (or do not exist). Literature data need to be collected to represent more closely what is happening at the field level in the national dairy industry. This study is a systematic analysis of the Brazilian dairy industry comparing data from scientific literature and breeders' association official controls, in order to understand differences between animals used in experiments and those in breed control assessments. There was a considerable lack of official data for most traits, and a large difference between official data and the literature. Literature data need to be collected that better represent what is happening at the field level in the national dairy industry. [ABSTRACT FROM AUTHOR]

Tudor staphylococcal nuclease (Tudor‐SN) participates in milk synthesis and cell proliferation in response to prolactin (PRL) and plays a regulatory role on mTOR phosphorylation. However, the complicated molecular mechanism of Tudor‐SN regulating milk protein synthesis and cell proliferation still remains to be illustrated. In present study, we observed that the proteins level of phosphorylated Tudor‐SN and phosphorylated STAT5 were simultaneously enhanced upon PRL treatment in bovine mammary epithelial cells (BMECs). Tudor‐SN overexpression and knockdown experiment showed that Tudor‐SN positively regulated the synthesis of milk protein, cell proliferation and the phosphorylation of STAT5, which was dependent on Tudor‐SN phosphorylation. STAT5 knockdown experiment showed that Tudor‐SN stimulated mTOR pathway through regulating STAT5 activation, which was required for PRL to activate the mTOR pathway. Thus, these results demonstrate the primary mechanism of Tudor‐SN coordinating with STAT5 to regulate milk protein synthesis and cell proliferation under stimulation of PRL in BMECs, which may provide some new perspectives for increasing milk production. [ABSTRACT FROM AUTHOR]

Soya–dairy protein blends can extend post-exercise muscle synthesis in young people more than whey protein control. Older adults differ metabolically from young people, and their ability to absorb amino acids from dietary protein is important for muscle function. The objective was to determine how protein source affects postprandial plasma amino acid response and/or metabolomic profile in older adults via a single-blind randomised crossover trial (n 16, males 50–70 years), using three nutritionally equivalent meal replacement drinks containing 30 g protein, from a 1:1 (mass ratio) soya:dairy blend, a 1:2 soya:dairy blend or whey protein. The outcome measures were plasma amino acid concentrations at 0–300 min postprandially and urine metabolomic fingerprint. Soya:dairy drinks gave similar amino acid response in plasma over time and similar urinary metabolite fingerprints. However, there were significant differences in plasma amino acid concentrations and AUC values for the soya:dairy drinks v. the whey protein drink. AUC for Leu, Trp and Lys was lower and AUC for Phe and Pro was higher for the soya:dairy drinks. Differences partly reflected the amino acid profiles of the drinks, but overall plasma amino acid response patterns were qualitatively unchanged. Plasma amino acid differences between the whey protein drink and the soya:dairy blends were reflected in urine metabolite patterns. In conclusion, postprandial plasma amino acid responses were broadly similar, irrespective of protein source (and soya:dairy ratio). There were significant differences for some plasma amino acid concentrations, reflecting different amino acid profiles of the protein source and influencing urine metabolite fingerprints. [ABSTRACT FROM AUTHOR]

Fruits and vegetables containing phenylalanine ≤ 75 mg/100 g (except potatoes) have little impact on blood phenylalanine in phenylketonuria (PKU). In a randomized, controlled, crossover intervention trial, we examined the effect of increasing phenylalanine intake from fruits and vegetables, containing phenylalanine 76–100 mg /100 g, compared with milk protein sources on blood phenylalanine control. This was a five-phase study (4 weeks each phase). In Phase A, patients remained on their usual diet and then were randomly allocated to start Phase B and C (an additional phenylalanine intake of 50 mg/day, then 100 mg from fruits and vegetables containing phenylalanine 76–100 mg/100 g) or Phase D and E (an additional phenylalanine intake of 50 mg/day then 100 mg/day from milk sources). There was a 7-day washout with the usual phenylalanine-restricted diet between Phase B/C and D/E. Blood phenylalanine was measured on the last 3 days of each week. If four out of six consecutive blood phenylalanine levels were >360 μmol/L in one arm, this intervention was stopped. Sixteen patients (median age 10.5 y; range 6–12 y) were recruited. At baseline, a median of 6 g/day (range: 3–25) natural protein and 60 g/day (range: 60–80) protein equivalent from protein substitute were prescribed. Median phenylalanine levels were: Phase A—240 μmol/L; Phase B—260 μmol/L; Phase C—280 μmol/L; Phase D—270 μmol/L and Phase E—280 μmol/L. All patients tolerated an extra 50 mg/day of phenylalanine from fruit and vegetables, containing phenylalanine 76–100 mg/100 g, but only 11/16 (69%) tolerated an additional 100 mg /day. With milk protein, only 8/16 (50%) tolerated an extra 50 mg/day and only 5/16 (31%) tolerated an additional 100 mg/day of phenylalanine. Tolerance was defined as maintaining consistent blood phenylalanine levels < 360 μmol/L throughout each study arm. There was a trend that vegetable protein had less impact on blood phenylalanine control than milk protein, but overall, the differences were not statistically significant (p = 0.152). This evidence supports the PKU European Guidelines cutoff that fruit and vegetables containing 76–100 mg phenylalanine/100 g should be calculated as part of the phenylalanine exchange system. Tolerance of the 'free use' of these fruits and vegetables depends on inter-patient variability but cannot be recommended for all patients with PKU. [ABSTRACT FROM AUTHOR]

Purpose: To investigate separate and combined effects of vitamin D supplementation during the extended winter and increased dairy protein intake on muscle strength and physical function in children, and furthermore to explore potential sex differences. Methods: In a 2 × 2-factorial, randomized winter trial, 183 healthy, 6–8-year-old children received blinded tablets with 20 µg/day vitamin D3 or placebo, and substituted 260 g/day dairy with yogurts with high (HP, 10 g protein/100 g) or normal protein content (NP, 3.5 g protein/100 g) for 24 weeks during winter at 55° N. We measured maximal isometric handgrip and leg press strength, and physical function by jump tests and a 30 s sit-to-stand test. Physical activity was measured by 7-day accelerometry. Results: Baseline (mean ± SD) serum 25-hydroxyvitamin D was 80.8 ± 17.2 nmol/L, which increased to 88.7 ± 17.6 nmol/L with vitamin D supplementation and decreased to 48.4 ± 19.2 nmol/L with placebo. Baseline protein intake was 15.5 ± 2.4 E%, which increased to 18.4 ± 3.4 E% with HP and was unchanged with NP. We found no separate or combined effects of vitamin D supplementation and/or increased dairy protein intake on muscle strength or physical function (all P > 0.20). There was an interaction on the sit-to-stand test (Pvitamin×yogurt = 0.02), which however disappeared after adjusting for physical activity (P = 0.16). Further, vitamin D supplementation increased leg press strength relatively more in girls compared to boys (mean [95% CI] 158 [17, 299] N; Pvitamin×sex = 0.047). Conclusion: Overall, vitamin D and dairy protein supplementation during the extended winter did not affect muscle strength or physical function in healthy children. Potential sex differences of vitamin D supplementation should be investigated further. Registered at clinicaltrials.gov: NCT0395673. [ABSTRACT FROM AUTHOR]

Milk proteins have received much awareness due to their bioactivity. However, their encapsulation functions have not attracted enough attention. Milk proteins as encapsulation walls can increase the bioavailability of bioactive compounds. As the benefits of bioactive compounds are critically determined by bioavailability, the effect of interactions between milk proteins and active substances is a critical topic. In the present review, we summarize the effects of milk proteins as encapsulation walls on the bioavailability of active substances with a special focus. The methods and mechanisms of interactions between milk proteins and active substances are also discussed. The evidence collected in the present review suggests that when active substances are encapsulated by milk proteins, the bioavailability of active substances can be significantly affected. This review also provides valuable guidelines for the use of milk protein-based microcarriers. [ABSTRACT FROM AUTHOR]

Nutrients in milk are abundant, and the rapid development of biomass spectrometry and bioinformatics algorithms has provided technical support to further elucidate nutrient content in milk such as N-glycoproteins, which are important post-translational modifications of proteins that have attracted significant research attention for their unique physicochemical and functional properties. We summarize the synthetic pathways of protein N-glycosylation, types of N-glycans, and primary distribution characteristics of N-glycoproteins in milk. Our review covers existing research of MS-based milk protein N-glycosylation in three dimensions: N-glycans, deglycosylated and intact N-glycopeptides obtained by enzymatic digestion of glycoproteins. A brief overview of protein N-glycosylation in dairy processing, absorption, and metabolism as well as biological functions is presented. The limitations and directions for future research on milk protein N-glycosylation are summarized. Intact N-glycopeptides obtained by enzymatic digestion of glycoproteins in current studies of milk protein N-glycosylation are insufficiently characterized and the construction of linkages between N-glycans and glycosylation sites must be further enhanced as a prerequisite for exploring milk protein N-glycosylation. N-glycosylation in dairy processing stabilizes protein conformation. Evidence from in vivo and in vitro studies suggests that milk protein N-glycans can be metabolised by intestinal microorganisms, modulate gut microbiota, reduce pathogen adhesion, regulate immune function, alleviate necrotizing enterocolitis, and affect brain development, with different structures having specific biological functions. However, more research is needed to validate existing findings. [Display omitted] • The state of research on milk protein N-glycosylation is outlined. • The structure and composition of milk protein N-glycans are compared systematically. • The N-glycosites and site-specific N-glycosylation in milk are reviewed. • The importance of milk protein N-glycosylation is discussed. • Future research trends for milk protein N-glycosylation are presented. [ABSTRACT FROM AUTHOR]

Background: Exosomes are involved in intercellular communication, affecting many physiological and pathological process. The present study evaluated the effects of serum exosomes on the function of bovine mammary epithelial cells (BMECs) and milk synthesis under heat stress. Methods and results: We cultured the BMECs in fetal bovine serum (FBS) or exosome-free FBS medium and examined, their viability using CCK-8 kit. The results showed that culturing the cells in an exosome-free medium decreased viability and increased the levels of reactive oxygen species. The BMECs cultured in the exosome-free medium had reduced mitochondrial membrane potential, decreased manganese superoxide dismutase activity, and disrupted mitochondrial dynamics. They exhibited apoptosis due to upregulated Drp1, Fis1, Bax and HSP70. Lastly, we observed downregulation of milk fat and lactoprotein-related genes: mTOR, PPARγ, p-mTOR and ADD1 and SREBP1, ELF5, and CSN2, respectively, after culturing the cells in an exosome-free medium. These negative effects of the exosome-free medium on the BMECs could be further reinforced under heat stress. Conclusion: Our results demonstrated that exosomes from serum are critical for maintaining the normal function of BMECs. [ABSTRACT FROM AUTHOR]

Objective: The Bagnolese sheep is an authochtonous dual-purpose breed (milk and meat) reared in the Campania region, whose milk is used to produce Pecorino Bagnolese cheese. Genetic information on this sheep is extremely limited, especially regarding genes affecting productions. The aim of this study was to investigate milk production traits in Bagnolese sheep and the variability of diacylglycerol acyltransferase 1 (DGAT1) gene and its effects on milk production., Methods: Milk quantity was recorded during the morning milking, while Kjeldahl and Gerber methods were used to assess protein and fat percentage (w/v) of collected milk samples. Two PCR-RFLP protocols using BamHI and MspI endonucleases for genotyping of g.5553C>T and g.8539C>T at DGAT1 locus, respectively, were set up., Results: Bagnolese sheep milk shows high fat and protein concentrations. Genotyping revealed a high frequency of the g.5553C and g.8539C alleles (0.56 and 0.95, respectively). The association study between the SNP g.5553C>T and milk traits showed that animals with the CT genotype had a higher percentage of fat produced per milking than those with the CC and TT genotypes (p<0.01). Similar results were found for protein yield percentage, with CT individuals being more productive than CC individuals (p<0.01)., Conclusion: Bagnolese sheep milk parameters found are associated with high yields in the resulting dairy products. CT genotype at the SNP g.5553 of DGAT1 has shown a positive association with fat and protein milk yield percentage suggesting it could be considered a marker to improve productions of this breed. Finally, the new genotyping techniques used for this study enable a cheap and reliable characterization of two DGAT1 SNPs in sheep.

Background: Postprandial vascular endothelial dysfunction is an early marker of atherosclerosis. Meal protein has been reported to reduce endothelial dysfunction in adults, and the effect could be mediated by the amino acid content., Objectives: This trial aims to assess the effect of a specifically designed plant-protein blend that contains high leucine, arginine, and cysteine on postprandial endothelial function in the elderly., Methods: In a randomized, double-blind, 3-period crossover (2-wk washout), controlled trial, we compared the vascular effects of 3 high-saturated-fat high-sucrose (HFHS) meals containing either our specific plant-protein blend, or milk protein, or without added protein. The trial was conducted on 29 healthy adults aged >65 y presenting ≥2 cardiometabolic risk factors. Postprandial vascular function was evaluated at fasting, 3 h, and 5 h postprandially, using brachial flow-mediated dilation (FMD), hand microvascular reactivity (using Flowmetry Laser Doppler, FLD), and finger reactive hyperemia index (using Peripheral Arterial Tonometry, RHI). Immune cell count and gene expression in peripheral blood mononuclear cells (PBMCs) were also assessed postprandially. Data were analyzed using mixed linear models with repeated measurements on participants for meal composition and time of sampling. This trial was registered at clinicaltrials.gov as NCT04923555., Results: FMD incremental AUC value decreased after meals (time effect P < 0.01), with no significant differences between meals. RHI also decreased with time (P < 0.01). PBMC count and monocyte chemoattractant protein-1 (MCP1), IL-1β, and IL-6 expression increased after meals showing postprandial endothelial activation (P < 0.05). Overall, meal composition had no effect on any of the postprandial changes (Ps>0.10)., Conclusions: In healthy adults aged >65 y presenting cardiometabolic risk, adding protein to an HFHS challenge meal does not mitigate postprandial impairments in vascular endothelial function and inflammatory activation. Further studies are needed to explore the potential differences with younger adults., Competing Interests: Conflict of interest The authors report no conflicts of interest., (Copyright © 2024 American Society for Nutrition. Published by Elsevier Inc. All rights reserved.)