Search Results (171)

This online survey aimed to gather consumer opinions on dairy products and production and to identify the potential market for A2 milk (milk containing exclusively β-casein A2, which reduces gastrointestinal discomfort after consumption). The questionnaire included seven sections covering the consumption of dairy products, sociodemographic aspects, awareness and purchase intention of A2 milk, questions about milk as a source of nutrients and health benefits, the environmental impact of milk production, and alternatives to cow milk. Responses from 672 Spanish consumers categorized into clusters (according to their milk consumption and their discomfort after drinking it), gender, age, educational level, and milk taste preference were analyzed using a linear multiple regression model. Dairy consumers not experiencing discomfort after drinking milk (62.6%) and those who preferred the taste of milk over plant-based alternatives (64.0%) demonstrated better knowledge of milk nutrients and its health benefits. Participants’ age, gender, and education level also influenced their perceptions, with older participants, women, and those with university education generally showing better results. In conclusion, clusters impact consumers’ milk perceptions as a nutritional source and its health benefits. The positive perception of milk’s nutritional benefits among dairy consumers experiencing discomfort after drinking milk (17.3%) positions them as a strong target market for A2 milk. Full article

The digestion of A1 β-casein present in conventional milk releases β-casomorphin-7 (βCM-7), a bioactive peptide with potential implications for gastrointestinal and neurological health. A scoping review was performed to respond to the following research question: What are the health effects of consuming milk containing the A1 β-casein variant compared to the exclusive consumption of the A2 variant in humans? The evidence collected in this review of human studies with different populations (i.e., children, middle-aged adults, athletes) suggests that the consumption of milk containing A1 β-casein may negatively influence gut health by altering microbial composition, reducing intestinal motility, and increasing colonic fermentation, leading to elevated gas production and altered short-chain fatty acid (SCFA) profiles. The release of βCM-7 upon digestion can also compromise intestinal-barrier integrity, which may exacerbate symptoms of lactose intolerance, irritable bowel syndrome (IBS), or other allergy-related sensitivities. Its ability to cross the blood–brain barrier raises concerns about potential neurological effects. In contrast, milk containing exclusively A2 β-casein is associated with improved gastrointestinal outcomes, including the enhanced abundance of beneficial bacteria such as Bifidobacterium spp. and reduced inflammatory markers. Full article

Goat caseins are highly polymorphic proteins that affect milk functional properties. In this study, an in silico approach was employed to analyze the influence of goat casein allelic variants on the quantity and bioactivity potential of peptides released after enzymatic hydrolysis. The reported protein sequences from the most frequent allelic variants in Capra hircus caseins (α-S1, β, α-S2, and κ-casein) were analyzed in the BIOPEP-UWM database to determine the frequency of occurrence of bioactive fragments from each casein. After specific hydrolysis with pepsin, trypsin, and chymotrypsin A, important differences in the peptide profile and bioactivity potential were observed within and between the casein allelic variants. The β-casein A and C alleles, α-S1-casein allele E, and α-S2-casein allele F presented the highest bioactivity potential, and some allele-specific peptides were also released, highlighting the impact of genotype on the predicted bioactivity. The inhibition of angiotensin-converting enzyme (ACE-I) and dipeptidyl peptidase IV (DPP-IV) activities was the most frequent bioactivity of the released peptides, suggesting possible antihypertensive and antidiabetic effects. Once confirmed by experimental studies, the use of goat casein genotyping could direct efforts to enhance the functional quality of goat milk. Full article

Background: The principal function of mammary glands is to produce milk to nourish the newborn. Optimal lactation is controlled by various hormones, growth factors, and cytokines. Objectives: Using 3D cultures of primary mouse mammary epithelial cells, we explored the effects of T helper (Th)1 cytokines, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α on the structure and function of mammary cells as well as the underlying mechanism. Methods: Three-dimensional cultures of mammary cells were treated with IFN-γ/TNF-α, and milk protein expression and acinar structures were analyzed by immunoblotting and immunofluorescence microscopy. Results: Our results revealed that combined treatment with IFN-γ and TNF-α inhibits prolactin-induced STAT5 tyrosine phosphorylation and β-casein expression. These cytokines also disrupted the structure of mammary acini, resulting in smaller or no lumens, disordered cell arrangements, and multilayered cells in certain regions. Additionally, some cells became elongated rather than maintaining their usual cube-like shape. Since cell proliferation and death can modulate the structural organization of acini, we examined the influences of IFN-γ and TNF-α on these events. Combined cytokine treatment moderately increased cell proliferation and cell death. Notably, stimulation with IFN-γ and TNF-α induced the expression of inducible nitric oxide synthase (iNOS), and the inhibition of iNOS partially restored acinar morphology and β-casein expression, revealing a novel mechanism for cytokine-induced acinar disruption. Conclusions: When a Th1 cytokine milieu is dominant, such as during inflammation and infection, IFN-γ and TNF-α might cause mammary gland ductal occlusion and lactation insufficiency. Full article

Background: Previous research indicates that gastrointestinal discomfort from milk consumption may be attributable to A1 β-casein, rather than lactose intolerance alone. A2 milk (free of A1 β-casein) consumption may result in fewer symptoms compared to conventional milk containing both A1/A2 β-casein. Objective: In this five-week, double-blind, double-crossover study, we assessed the physiological responses to doses escalating in volume of lactose-free conventional milk (Lactaid), A2 milk, and lactose-free A2 milk in fluid milk-avoiding participants. Methods: Each milk type was consumed over three separate weeks with three increasing doses across five days per week, >one week washout. Gastrointestinal symptoms, blood glucose, and breath gases were monitored for twenty-four, two-, and three-hours post-consumption, respectively. Sensory evaluation was completed for each sample. Results: Fifty-three participants consented and were randomized, with forty-eight participants completing the study. Overall, symptoms were minimal. On Days 1 and 3, lower ratings of bloating and flatulence were observed in A2 compared to lactose-free A2. Breath hydrogen responses reflected lactose content, but were higher in lactose-free A2 than Lactaid on Day 5. Thirty-three participants were deemed lactose-intolerant and had higher fasting and average breath hydrogen for all samples. The only symptom corresponding to the increase in breath hydrogen among these participants was flatulence after A2 consumption. Surprisingly, flatulence was apparently higher for lactose-tolerant individuals when consuming Lactaid compared to A2. Conclusions: These findings suggest that adults who avoid conventional fluid milk consumption may experience minimal GI discomfort from lactose-free and/or A1-free milks. Full article

Mastitis significantly impacts both the yield and quality of milk. The somatic cell count (SCC) and differential somatic cell count (DSCC), which are related to immune cells, are primary indicators for assessing mammary gland health. In this study, eight previously established mid-infrared spectroscopy models were utilized to predict the content of milk protein fractions (αs1-CN, β-CN, κ-CN, total CN, α-LA, β-LG, IgG, and LF) in milk samples from 21,388 lactating cows across 33 herds. Four linear mixed models were applied to analyze the secretion patterns of milk protein fractions by days in milk (DIM) and parity, their variations under different mastitis conditions, and their associations with the somatic cell score (SCS), DSCC, and immune cell counts (PMN + LYM score (PMN + LYMS) and MAC score (MACS)). The primary findings of the investigation comprised the following: (1) IgG was higher in early lactation, decreased with advancing lactation days, and slightly increased in late lactation, while seven other protein factions decreased from early to peak lactation and increased during mid-to-late lactation. Parity influenced all milk protein fractions except αs1-CN, with total CN, β-CN, and α-LA decreasing and κ-CN, β-LG, IgG, and LF increasing as parity increased (p < 0.05). (2) Mastitis significantly reduced the milk yield, fat percentage, protein percentage, and the contents of total CN, β-CN, κ-CN, and α-LA while increasing β-LG, IgG, and LF. (3) The SCS was negatively correlated with milk yield and α-LA but positively correlated with the fat percentage, protein percentage, κ-CN, β-LG, IgG, and LF. (4) When the DSCC increased to 50%, the milk yield decreased, while the milk protein percentage and κ-CN content significantly increased (p < 0.05). When the DSCC exceeded 50%, the fat percentage, protein percentage, total casein, αs1-CN, β-CN, κ-CN, β-LG, IgG, and LF decreased, while the α-LA content increased (p < 0.05). (5) When the PMN + LYMS increased, the milk yield and α-LA content rose, while the milk fat percentage, the milk protein percentage, and the contents of αs1-CN, β-CN, κ-CN, total CN, β-LG, IgG, and LF decreased (p < 0.05). Conversely, when the MACS increased, the milk yield and α-LA content declined, whereas the milk fat percentage, the milk protein percentage, and the contents of αs1-CN, β-CN, κ-CN, total CN, β-LG, IgG, and LF increased (p < 0.05). This study offers valuable insights into enhancing milk product quality, advancing the early diagnosis and mechanistic research of bovine mastitis, and the sustainable development of the dairy farming industry. Full article

This study investigated the IgA antibodies targeting bovine serum albumin (BSA) in 27 adult celiac disease (CD) patients adhering to a gluten-free diet (GFD), compared to 123 controls (including individuals with autoimmune disorders, those with gastrointestinal cancers, and healthy donors). Serum samples were evaluated using a multiplex assay based on a microarray comprising 66 immobilized antigens, including autoantigens associated with autoimmune diseases, different albumins, cytokines, and inflammatory markers. Elevated IgA-BSA levels were detected in 22% of CD patients versus 3.25% of controls. IgA-BSA did not cross-react with milk proteins like casein, β-lactoglobulin, and γ-globulin, nor with autoantigens and human albumin, ruling out autoimmunity against self-proteins. The observed cross-reactivity with porcine albumin suggests that antibodies target epitopes shared by bovine and porcine albumin. Increased IgA-BSA levels may interfere with immunoassays performed using BSA as a stabilizer, necessitating protein-free buffers to avoid false results when testing CD patients. Elevated IgA-BSA levels may reflect ongoing gut barrier dysfunction in CD patients on a GFD, allowing dietary proteins like BSA to trigger immune responses. This study identifies a novel immune response in CD patients on a GFD, emphasizing the need for tailored diagnostic approaches (BSA-free assays) and further research into the clinical and dietary implications of IgA-BSA elevation. Full article

Background: Cow’s milk is the most frequent cause of food allergies in children, with caseins and β-lactoglobulin being considered the main allergens. Concerningly, numerous international agencies have highlighted a growing risk of allergic reactions in milk-allergic individuals after the consumption of products labelled as “vegan”. Objectives: We describe the case of a 3.5-year-old boy with a history of a food allergy to milk who complained of anaphylactic clinical symptoms after eating a vegan Easter egg. The aim of this study was to confirm the cause of the clinical symptoms, searching for the possible presence of milk proteins in the vegan chocolate. Methods: An experimental approach based on electrophoretic (SDS-PAGE) and immunoenzymatic techniques (ELISA) was applied. Results: SDS-PAGE indicated the presence of milk proteins, which was confirmed and quantified via ELISA (3034 ± 115 mg/kg). Conclusions: The data obtained demonstrate that the severe clinical symptoms were due to the unexpected presence of milk proteins in a vegan product, underlining the critical need for rigorous allergen quality control throughout the food industry. Full article

Bovine milk protein preparations (MPPs), namely micellar casein concentrate (MCC), serum protein concentrate (SPC), and MCC with ultrafiltrated buttermilk permeate (MBP), were analyzed as sources of inhibitors of angiotensin-converting enzyme (i.e., ACE) and dipeptidylpeptidase IV (i.e., DPP-IV) as well as antioxidative peptides. The studies involved in silico predictions of the release of biopeptides from bovine milk proteins. Then, all MPPs were subjected to the simulated gastrointestinal digestion using the INFOGEST protocol. Results using a BIOPEP-UWM database tool indicated that 59 biopeptides exhibiting the above-mentioned activities could be produced upon the action of pepsin, trypsin, and chymotrypsin. Thirty-six biopeptides were identified in at least one of the three MPPs subjected to the INFOGEST protocol. MCC before simulated digestion exhibited the strongest ACE-inhibiting activity among all MPPs (IC₅₀ = 1.856 mg/mL). The weakest ACE inhibitory effect was demonstrated for MBP after duodenal digestion (i.e., MBP D; IC₅₀ = 7.627 mg/mL). The above MPP showed the strongest DPP-IV-inhibiting activity (IC₅₀ = 0.0067 mg/mL). All MPPs exhibited antioxidative activity, with the strongest ABTS^•+ (i.e., 2,2′-azino-bis(3-ethylbenzotialozline-6-sulfonic acid) radical scavenging effect shown for MBP D (IC₅₀ = 2.754 mg/mL), and the strongest DPPH^• (i.e., 2,2-diphenyl-β-picrylhydrazyl) radical scavenging activity (IC₅₀ = 1.238 mg/mL) demonstrated for SPC D. Among all MPPs, SPC D also exhibited the highest FRAP (i.e., Ferric Reducing Antioxidant Power) bioactivity (IC₅₀ = 13.720 mg/mL), whereas MBP D was the MPP with the lowest FRAP potential (IC₅₀ = 20.140 mg/mL). The present study results show the potential of all MPPs as functional additives to support health-beneficial functions of dairy products. Full article

The dairy industry relies on the health and well-being of dairy cows for the optimal production of milk and dairy products. Mastitis, a prevalent and economically burdensome disease characterized by udder inflammation, poses significant challenges to dairy farmers worldwide. In this study, we employed peptidomics to explore the peptide profiles of dry secretions collected from dairy cows at specific intervals during the dry-off period. We hypothesized that alterations in peptide composition during the dry period may influence pathogen proliferation and immune cell functioning, thereby impacting mastitis susceptibility. Our objectives were to investigate the following: (i) differences in peptide composition and alterations between healthy cows and those with subclinical mastitis, potentially serving as biomarkers for early mastitis detection and offering insights into udder bioprocesses; (ii) variations in peptide profiles between the early (day 2) and later (day 21) stages of the dry-off period during both health conditions. Dry secretions were collected from 16 udder quarters of 8 cows at two defined time points—Day 2 (D2) and Day 21 (D21)—during the dry period. Our results revealed distinct peptide patterns between healthy and subclinical mastitis cows, as well as temporal variations in peptide profiles throughout the dry-off period. A total of 1235 peptides, originating from 59 distinct proteins (primarily β-casein), were detected across the four groups: subclinical mastitis day 21 (SCM-D21), subclinical mastitis day 2 (SCM-D2), healthy day 21 (H-D21), and healthy day 2 (H-D2). Furthermore, 56 out of the 1235 peptides identified in total matched known functional peptides, with a total of 17 different functions including antimicrobial, antioxidant, and immunomodulatory, suggesting their potential roles in mastitis pathogenesis and mammary gland physiology. Comparative analyses revealed changes in the levels of these functional peptides across the four different groups, suggesting their potential roles in regulating immune responses, oxidative stress, inflammatory processes, and other biological activities during subclinical mastitis and the dry-off period. These findings provide valuable insights into mastitis detection, management strategies, and dairy cow health monitoring, offering promising avenues for enhancing milk quality and dairy industry sustainability. Full article

Background/Objectives: Research on postbiotics derived from probiotic fermented milk bases require further expansion, and the mechanisms through which they exert their effects have yet to be fully elucidated. This study utilized in vitro cell co-culture, digestion, and fermentation experiments, combined with targeted T500 technology, to elucidate the mechanism by which postbiotic Pa JY062 safeguards intestinal health. Compared to the LPS group, Pa JY062 boosted phagocytic ability in RAW264.7 macrophages, decreased NO levels, and alleviated LPS-induced excessive inflammation. Pa JY062 suppressed pro-inflammatory cytokines (IL-6, IL-17α, and TNF-α) while elevating anti-inflammatory IL-10. It prevented LPS-induced TEER reduction in Caco-2 monolayers, decreased FITC-dextran permeability, restored intestinal microvilli integrity, and upregulated tight junction genes (ZO-1, occludin, claudin-1, and E-cadherin). The hydrolysis rate of Pa JY062 progressively rose in gastrointestinal fluids in 0–120 min. At 5 mg/mL, it enriched gut microbiota diversity and elevated proportions of Limosilactobacillus, Lactobacillus, Pediococcus, and Lacticaseibacillus while augmenting the microbial production of acetic acid (120.2 ± 8.08 μg/mL), propionic acid (9.9 ± 0.35 μg/mL), and butyric acid (10.55 ± 0.13 μg/mL). Pa JY062 incorporated α_s-casein/β-lactoglobulin hydrolysate (L-glutamic acid, alanine, lysine, tyrosine, phenylalanine, histidine, and arginine) to mitigate protein allergenic potential while harboring bioactive components, including tryptophan metabolites, vitamin B6 (VB6), and γ-aminobutyric acid (GABA). Pa JY062 represented a novel postbiotic with demonstrated intestinal health-promoting properties. These findings advance the current knowledge on postbiotic-mediated gut homeostasis regulation and expedite the translational development of dairy-derived postbiotic formulations. Full article

Mycotoxins are frequent food contaminants posing health risk to humans and animals. Since these interactions have been barely studied yet, we examined the potential complex formation of mycotoxins with human α₁-acid glycoprotein (AGP) and with bovine milk proteins (including casein (CSN), β-lactoglobulin (LG), and α-lactalbumin (LA)) based on fluorescence spectroscopic and ultracentrifugation techniques. Only weak interactions (logK = 2.7 to 3.5) of certain mycotoxins were observed with CSN, LG, and/or LA. Ultracentrifugation experiments demonstrated that aflatoxin M1, zearalenone, and α-zearalenol form more stable complexes with CSN than with LG or LA. These mycotoxins bound to bovine serum albumin with more than a tenfold higher affinity compared to CSN; nevertheless, it has likely limited importance due to the relatively low levels of BSA in bovine milk. Zearalenone, zearalenols, and sterigmatocystin showed strong interactions with AGP (logK = 5.5 to 6.4), suggesting that AGP may play an important role in the plasma protein binding of these mycotoxins. Full article

Cow’s milk allergy (CMA) is the most common food allergy in infants. This study aimed to identify peptide biomarkers predictive of tolerance in a Spanish population of children with CMA. We investigated specific IgE and IgG4 binding to sequential epitopes of the five major CM allergens (α-s1-, α-s2-, β-, and κ-caseins as well as β-lactoglobulin) using a microarray-based immunoassay. Microarray analysis was performed in 118 patients at baseline and after 6, 18, 30, 42, and 54 months. Most patients tolerated CM at 6 months (40.7%) and 18 months (35.4%). We found significant differences in IgE and IgG4 binding intensity and diversity between allergic and tolerant patients. No differences were observed at baseline. Combining baseline IgE and IgG4 serology variables and peptide microarray analysis results, a predictive model was developed using the XGBoost algorithm to classify tolerance status at different time points. The generated models showed high predictive value at 6 and 30 months with AUCs of 0.883 and 0.833, respectively. Therefore, using IgE and IgG4 antibody-binding peptides at baseline, we generated two models predicting tolerance in children with cow’s milk allergy at 6 and 30 months. Full article

This study critically examines the limitations of the official Italian methodology used for detecting bovine adulteration milk in Protected Designation of Origin (PDO) Mozzarella di Bufala Campana (MdBC). This method focuses on the whey fraction of cheese samples, which comprises about 1% of total MdBC proteins, and is based on a high-performance liquid chromatography (HPLC) quantification of the bovine β-lactoglobulin A (β-Lg A) as a marker. Here, we have demonstrated that this official methodology suffers from measurement inconsistencies due to its reliance on raw bovine whey standards, which fail to account for β-Lg genetic polymorphisms in real MdBC samples and protein thermal modifications during cheesemaking. To overcome these limitations, we propose a dual proteomics-based approach using matrix-assisted laser desorption ionization (MALDI-TOF) mass spectrometry (MS) and nano-HPLC-electrospray (ESI)−tandem mass spectrometry (MS/MS) analysis of MdBC extracted whey. MALDI-TOF-MS focused on identifying proteotypic peptides specific to bovine and buffalo β-Lg and α-lactalbumin (α-La), enabling high specificity for distinguishing the two animal species at adulteration levels as low as 1%. Complementing this, nano-HPLC-ESI-MS/MS provided a comprehensive profile by identifying over 100 bovine-specific peptide markers from β-Lg, α-La, albumin, lactoferrin, and osteopontin. Both methods ensured precise detection and quantification of bovine milk adulteration in complex matrices like pasta filata cheeses, achieving high sensitivity even at minimal adulteration levels. Accordingly, the proposed dual proteomics-based approach overcomes challenges associated with whey protein polymorphism, heat treatment, and processing variability, and complements casein-based methodologies already validated under European standards. This integrated framework of analyses focused on whey and casein fraction enhances the reliability of adulteration detection and safeguards the authenticity of PDO buffalo mozzarella, upholding its unique quality and integrity. Full article

This study examined the effect of low-frequency ultrasound (20 kHz, 1 and 5 min) on the physiochemical and structural properties of milk powder formulations with varying casein to whey ratios (0:100, 60:40, and 50:50) and calcium addition (30 mM). The ultrasound treatment led to changes in particle size, with an initial increase in aggregation followed by fragmentation. Calcium addition resulted in looser packing, as evidenced by a decrease in both bulk and tapped densities. DSC analysis indicated that calcium addition stabilized the protein–lactose matrix by increasing the glass transition temperature and reducing the number of thermal events. FTIR analysis revealed structural changes in proteins, with a decrease in β-sheet and β-turn and an increase in α-helix structures. These findings suggest that calcium plays a crucial role in reinforcing the structural integrity of the protein–lactose matrix, while ultrasound-induced mechanical forces lead to dynamic changes in particle size and protein conformation. Full article