Changes in milk fat globule membrane proteome after pasteurization in human, bovine and caprine species

Differences in proteomic profiles and immunomodulatory activity of goat and cow milk fat globule membrane

This study aimed to clarify the composition and bioactivity differences between goat and cow milk fat globule membrane (MFGM) protein by proteomic, and the immunomodulatory activity of MFGM proteins was further evaluated by using mouse splenic lymphocytes in vitro. A total of 257 MFGM proteins showed significant differences between goat and cow milk. The upregulated and unique MFGM proteins in goat milk were significantly enriched in the positive regulation of immune response, negative regulation of Interleukin-5 (IL-5) secretion, and involved in nucleotide-binding oligomerization domain (NOD)-like receptor signaling. The contents of IL-2 and Interferon-γ in the supernatant of spleen lymphocytes treated with goat MFGM proteins were much higher than those of IL-4 and IL-5, suggesting a Th1-skewed immune response. These results revealed that goat MFGM proteins could possess better immunomodulatory effects as compared to cow milk. Our findings may provide new insights to elucidate the physiological functions and nutritional of goat milk.

Application of pressure homogenization on whole human milk pasteurized by high hydrostatic pressure: Effect on protein aggregates in milk fat globule membrane and skim milk phases

This study explored the impact of homogenization (at pressures of 16, 30, and 45 MPa) on both raw and high hydrostatic pressure (HHP)-treated human milk (HM). It focused on protein compositions and binding forces of soluble and insoluble fractions for both milk fat globule membrane (MFGM) and skim milk. Mild homogenization of HHP-treated milk increased lactoferrin (LF) levels in the insoluble fractions of both MFGM and skim milk, due to insoluble aggregation through hydrophobic interactions. Intense homogenization of HHP-treated milk decreased the LF level in the MFGM fractions due to the LF desorption from the MFGM, which increased LF level in the insoluble skim milk fraction. Homogenized-HHP treated milk showed noticeably higher casein (CN) level at the MFGM compared to homogenized-raw milk, attributed to HHP effect on CN micelles. Overall, the combined use of HHP and shear-homogenization should be avoided as it increased the biological proteins in insoluble fractions.

Heat-stable whey protein isolate made using isoelectric precipitation and clarification

Residual lipids (RL) in whey protein isolate (WPI) are detrimental to optimal functional applications (e.g., foaming and low turbidity) and contribute to off-flavor development during powder storage. The objective of this research was to prepare an experimental WPI by removing RL without using the traditional microfiltration process and compare its properties with commercially available WPI made using microfiltration and some other whey powders. We hypothesize that by adjusting the pH of whey to <5.0, we would be close to the isoelectric point of any remaining denatured proteins (DP) and phospholipoproteins (PLP), and therefore reduce electrostatic repulsion between these molecules. Furthermore, demineralization of the acidified whey protein solution by UF combined with diafiltration (DF) should reduce ionic hindrance to aggregation and thereby help with the aggregation of these DP as well as most RL; centrifugation or clarification could be used to remove these materials. Calcium should also be more extensively removed by this approach, which should improve the heat stability of the experimental WPI. Demineralization was achieved on a pilot scale by acidifying liquid (cheese) whey protein concentrate containing 34% protein (WPC-34) to pH 4.5 using HCl, and UF of the whey protein solution along with extensive DF using acidified (pH ∼3.5) reverse osmosis filtered water. Demineralized whey protein solution was adjusted to various combinations of pH (4.1-4.9), conductivities (500-2,000 μS/cm), and protein concentrations (1%-7%) and then centrifuged at 10,000 × g for 10 min. The effective sedimentation (precipitation) of RL in these treatments was estimated by measuring the turbidity of the supernatants. Maximum precipitation was observed at pH 4.5 to 4.7. Reducing conductivity via UF/DF increased the precipitation of RL due to reduced ionic hindrance to aggregation. Maximum sedimentation of RL was observed at protein concentrations ≤3% because of a higher density difference between the precipitate and serum phase. Analysis by sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis confirmed the sedimentation of phospholipoproteins, caseins, and DP upon isoelectric precipitation at pH ∼4.5, while native whey proteins or undenatured whey proteins remained soluble in the supernatant, unaffected by the pretreatment. To scale up the process, 750 L of fluid WPC-34 was acidified and demineralized by UF (volume concentration factor = 1.35) and DF until the permeate solids reached 0.1% (when desired demineralization was achieved), clarified using a pilot-scale desludging clarifier to remove RL, neutralized, ultrafiltered to concentrate the protein, and then spray-dried to produce an experimental WPI (91% protein and 1.8% fat on a dry basis [db]). In another trial, demineralized UF concentrate was clarified by gravity sedimentation and the supernatant was neutralized, ultrafiltered, and spray-dried to produce a second experimental WPI (91% protein and <1% fat db). These experimental WPI powders were compared with several commercially available WPI powders to assess functional properties such as solubility, heat stability, foamability and foam strength, gelation, and sensory attributes over accelerated storage. Experimental WPI had excellent functional properties, had low turbidity, were highly heat stable, and only developed very slight-to-slight off-flavors upon accelerated storage, and their properties were comparable to the WPI manufactured commercially using microfiltration even after accelerated storage.

Comprehensive review of milk fat globule membrane proteins across mammals and lactation periods in health and disease

Milk fat globule membrane (MFGM) is a three-layer membrane-like structure encasing natural milk fat globules (MFGs). MFGM holds promise as a nutritional supplement because of the numerous physiological functions of its constituent protein. This review summarizes and compares the differences in MFGM protein composition across various species, including bovines, goats, camels, mares, and donkeys, and different lactation periods, such as colostrum and mature milk, as assessed by techniques such as proteomics and mass spectrometry. We also discuss the health benefits of MFGM proteins throughout life. MFGM proteins promote intestinal development, neurodevelopment, and glucose and lipid metabolism by upregulating tight junction protein expression, brain function-related genes, and glucose and fatty acid biosynthesis processes. We focus on the mechanisms underlying these beneficial effects of MFGM proteins. MFGM proteins activate key substances in in signaling pathways, such as the phosphatidylinositol 3-kinase/protein kinase B, mitogen-activated protein kinase, and myosin light chain kinase signaling pathways. Overall, the consumption of MFGM proteins plays an essential role in conferring health benefits, some of which are important throughout the mammalian life cycle.

Full-fat dairy products and cardiometabolic health outcomes: Does the dairy-fat matrix matter?

Reducing dairy fat intake is a common dietary guideline to limit energy and saturated fatty acid intake for the promotion of cardiometabolic health. However, research utilizing a holistic, food-based approach to assess the consumption of the fat found in dairy, a broad and diverse food group, may provide new insight into these guidelines. Dairy fat is comprised of a diverse assembly of fatty acids, triacylglycerols, sterols, and phospholipids, all uniquely packaged in a milk fat globule. The physical structure of this milk fat globule and its membrane is modified through different processing methods, resulting in distinctive dairy-fat matrices across each dairy product. The objectives of this narrative review were to first define and compare the dairy-fat matrix in terms of its unique composition, physical structure, and fat content across common dairy products (cow's milk, yogurt, cheese, and butter). With this information, we examined observational studies and randomized controlled trials published within the last 10 years (2013-2023) to assess the individual effects of the dairy-fat matrix in milk, yogurt, cheese, and butter on cardiometabolic health and evaluate the implications for nutrition guidance. Searches conducted on Ovid MEDLINE and PubMed® utilizing search terms for cardiometabolic health, both broadly and regarding specific disease outcomes and risk factors, yielded 59 studies that were analyzed and included in this review. Importantly, this review stratifies by both dairy product and fat content. Though the results were heterogeneous, most studies reported no association between intake of these individual regular-fat dairy products and cardiometabolic outcome measures, thus, the current body of evidence suggests that regular-fat dairy product consumption may be incorporated within overall healthy eating patterns. Research suggests that there may be a beneficial effect of regular-fat milk and yogurt intake on outcome measures related to body weight and composition, and an effect of regular-fat cheese intake on outcome measures related to blood lipids, but more research is necessary to define the directionality of this relationship. Lastly, we identify methodological research gaps and propose future research directions to bolster the current evidence base available for ascertaining the role of dairy fat in a healthy diet.

Identification of pasteurized mare milk and powder adulteration with bovine milk using quantitative proteomics and metabolomics approaches

Adulteration in dairy products presents food safety challenges, driven by economic factors. Processing may change specific biomarkers, thus affecting their effectiveness in detection. In this study, proteomics and metabolomics approaches were to investigate the detection of bovine milk (BM) constituents adulteration in pasteurized mare milk (PMM) and mare milk powder (MMP). Several bovine proteins and metabolites were identified, with their abundances in PMM and MMP increasing upon addition of BM. Proteins like osteopontin (OPN) and serotransferrin (TF) detected adulteration down to 1 % in PMM, whereas these proteins in MMP were utilized to identify 10 % adulteration. Biotin and N6-Me-adenosine were effective in detecting adulteration in PMM as low as 10 % and 1 % respectively, while in MMP, their detection limits extend down to 0.1 %. These findings offer insights for authenticating mare milk products and underscore the influence of processing methods on biomarker levels, stressing the need to consider these effects in milk product authentication.

A study of the effect of hypothyroidism during pregnancy on human milk quality based on rheological properties

Hypothyroidism has been found to have an effect on the nutritional composition of human milk during pregnancy. This study aims to explore the combined influence of rheological properties, macronutrient content, particle size, and the zeta potential of milk fat globules, as well as the composition of milk fat globule membrane (MFGM) proteins on the quality of human milk in gestational hypothyroidism. The study revealed that human milk from the group with hypothyroidism during pregnancy (AHM) was less viscoelastic and stable when compared with normal pregnancy group human milk (NHM). Furthermore, the particle size and macronutrient content of NHM were found to be larger than that of AHM. In contrast, the zeta potential of AHM was greater than that of NHM. The sodium dodecyl sulfate-PAGE results disclosed that the composition of MFGM proteins in these 2 groups were generally the same, but the content of AHM was lower than that of NHM. In conclusion, this study confirms that hypothyroidism during pregnancy can have a significant effect on the quality of human milk.

Milk fat globule membrane proteins are crucial in regulating lipid digestion during simulated in vitro infant gastrointestinal digestion

Products of lipolysis released during digestion positively affect the metabolism of newborns. In contrast to the 3-layer biological membranes covering human milk (HM) fat, the lipid droplets in infant milk formula (IMF) are covered by a single membrane composed of casein and whey proteins. To reduce the differences in lipid structure between IMF and HM, studies have used milk fat globule membrane (MFGM) components such as milk polar lipids (MPL) to prepare emulsions mimicking HM fat globules However, few studies have elucidated the effect of membrane proteins (MP) on lipid digestion in infants. In this study, 3 kinds of emulsions were prepared: One with MPL as the interfaced of lipid droplets (RE-1), one with membrane protein concentrate (MPC) (RE-2) as the interface of lipid droplets, and one with both MPL and MPC (1:2) as the co-interface of lipid droplets (RE-3). The interfacial coverage of the emulsions was confirmed by measuring the contents of MPL and MPC at the lipid droplet interface, and by confocal laser scanning microscopy analyzed. By controlling the homogenization intensity, the specific surface area of lipid droplets was controlled at the same level among the 3 emulsions. The stability constants of the emulsions varied, and RE-1 was the most stable. During simulated in vitro infant gastrointestinal digestion, the amount of free fatty acids (FFA) released from the lipid droplets was significantly higher from those with MPC at the interface (RE-2, RE-3) than from that with MPL at the interface (RE-1). The amount of FFA released at the end of intestinal digestion of RE-1, RE-2, and RE-3 was 255.00 ± 3.54 µmol,328.75 ± 5.30 µmol, 298.50 ± 9.19 µmol, respectively. Compared with the lipid droplets in RE-2, those with MPL at the interface (RE-1, RE-3) released more unsaturated fatty acids (USFAs) during digestion. The emulsifying activity index was highest in RE-3 (MPL and MPC co-interface). The presence of MPL at the emulsion interface increased the release of USFAs, while the presence of MPC increased the release of FFA. These results show that both MPL and MP are indispensable in the construction of MFGM. Understanding their effects on digestion can provide new strategies for the development of infant foods.

Comparison of the Lipid Composition of Milk Fat Globules in Goat (Capra hircus) Milk during Different Lactations and Human Milk

Goat milk is considered the optimal substitute for human milk and is characterized by variations in the lipid composition of its fat globules across lactation phases. Therefore, the objective of this study was to thoroughly analyze the differences between goat milk during different lactations and human milk, aiming to offer scientific guidance for the production of functional dairy products. Compared with transitional and mature milk, the findings indicated that the total membrane protein content in goat colostrum exhibited greater similarity to that found in human milk. Additionally, goat milk exhibited higher milk fat globule size, as well as a higher total lipid and protein content than human milk. A total of 1461 lipid molecules across 61 subclasses were identified in goat milk and human milk. The contents of glycerides and glycerophospholipids were higher in goat colostrum, whereas sphingolipids and fatty acids were more abundant in human milk. Meanwhile, the compositions of lipid subclasses were inconsistent. There were 584 differentially expressed lipids identified between human and goat milk, including 47 subclasses that were primarily involved in the metabolism of glycerophospholipids, sphingolipids, and triglycerides. In summary, for both the membrane protein and the lipid composition, there were differences between the milk of different goat lactations and human milk.

Identification and comparison of milk fat globule membrane and whey proteins from Selle Français, Welsh pony, and Tieling Draft horse mare's milk

Horse's milk, with a high nutritional value and few allergenic proteins, could substitute cow's milk for infant consumption. Herein, a label-free, proteomic method was used to identify and compare milk fat globule membrane (MFGM) and whey proteins from three different horse breeds: Selle Français (SF), Welsh pony (WP), and Tieling Draft Horse (TDH). In MFGMs, 16 (SF), 66 (WP), and 45 (TDH) unique proteins were identified, which are involved in the endocytosis, ribosome, and staphylococcus aureus infection pathways, respectively. In whey, 31 (SF), 75 (WP), and 23 (TDH) unique proteins were identified, which are involved in the autophagy-animal, phenylalanine metabolism, and Vasopressin-regulated water reabsorption pathways, respectively. SF contained the lowest concentration of β-lactoglobulin, which can cause allergic reactions in humans. Our findings describe the nutritional differences and functional diversities of MFGM and whey proteins in different horse breeds, which could support developing formula more suitable for human infants.

Preventative Effects of Milk Fat Globule Membrane Ingredients on DSS-Induced Mucosal Injury in Intestinal Epithelial Cells

The goblet cells of the gastrointestinal tract (GIT) produce glycoproteins called mucins that form a protective barrier from digestive contents and external stimuli. Recent evidence suggests that the milk fat globule membrane (MFGM) and its milk phospholipid component (MPL) can benefit the GIT through improving barrier function. Our objective was to compare the effects of two digested MFGM ingredients with or without dextran sodium sulfate (DSS)-induced barrier stress on mucin proteins. Co-cultured Caco-2/HT29-MTX intestinal cells were treated with in vitro digests of 2%, 5%, and 10% (w/v) MFGM or MPL alone for 6 h or followed by challenge with 2.5% DSS (6 h). Transepithelial electrical resistance and fluorescein isothiocyanate (FITC)-dextran (FD4) permeability measurements were used to measure changes in barrier integrity. Mucin characterization was performed using a combination of slot blotting techniques for secreted (MUC5AC, MUC2) and transmembrane (MUC3A, MUC1) mucins, scanning electron microscopy (SEM), and periodic acid Schiff (PAS)/Alcian blue staining. Digested MFGM and MPL prevented a DSS-induced reduction in secreted mucins, which corresponded to the prevention of DSS-induced increases in FD4 permeability. SEM and PAS/Alcian blue staining showed similar visual trends for secreted mucin production. A predictive bioinformatic approach was also used to identify potential KEGG pathways involved in MFGM-mediated mucosal maintenance under colitis conditions. This preliminary in silico evidence, combined with our in vitro findings, suggests the role of MFGM in inducing repair and maintenance of the mucosal barrier.

Characterization of protein aggregates in cream and skimmed human milk after heat and high-pressure pasteurization treatments

Preservation processes applied to ensure microbial safety of human milk (HM) can modify the native structure of proteins and their bioactivities. Consequently, this study evaluated the effect of pasteurization methods (Holder pasteurization, high-temperature short-time (HTST), and high hydrostatic pressure (HHP)) of whole human milk (HM) on protein aggregates in skim milk and cream fractions. For heat-treated whole milk, insoluble protein aggregates at milk fat globule membrane (MFGM) were formed by disulfide and non-covalent bonds, but insoluble skim milk protein aggregates were only stabilized by non-covalent interactions. Contrary to heat treatment, the insolubilization of main proteins at the MFGM of HHP-treated HM was only through non-covalent interactions rather than disulfide bonds. Moreover, only heat treatment induced the insoluble aggregation of ⍺-lactalbumin. Overall, compared to heat treatment, HHP produced a milder effect on protein aggregation, validating the use of this process to better preserve the native state of HM bioactive proteins.

A comparison of milk fat globule membranes and whey proteomes: New insight into variation nutrient differences between Buffalo, Cow, Goat, and Yak

In this study, the whey and milk fat globule membrane (MFGM) proteomes of buffalo, cow, goat, and yak milk were analyzed using label-free proteomic technology. Totally, 1,292 MFGM proteins and 686 whey proteins were identified from these four species, and GO analysis revealed there were specific proteins with different functions in both whey (376) and MFGM (982) proteomes. The principal component analysis showed that ALB, TF, CSN1S1, and GLYCAM1 are characteristic markers of the milk for each of the four species. Furthermore, the conserved and differential in the expression of whey and MFGM proteins across the four species were identified by limma, and subsequent KEGG pathway analysis showed that immune-related proteins are both conserved and species-specific in the four species. These results provide a deepening of the understanding of the characteristics of proteins in whey and MFGMs from these four common dairy animals and new insight into developing dairy production.

A novel strategy to construct stable fat globules with all major milk fat globule membrane proteins to mimic breast milk fat emulsions at the protein level

Milk fat globule membrane (MFGM) proteins have several biological functions and maintain the fat globule structure. However, the major MFGM protein compositions in simulated human milk emulsions are different from those in human milk due to the composition loss in the isolation process of MFGM materials. To overcome this limitation, we developed a novel strategy, namely, the solution enriched with MFGM was homogenized with cream separated from the milk rich in large-sized fat globules. The results of physicochemical properties and the interfacial protein coverage of the emulsions showed that the emulsions prepared by the new method had a smaller particle size, higher stability, and more interfacial protein coverage when the ratio of fat to protein was 1:3. In addition, proteome differences in interfacial proteins between the new emulsions and simulated infant formula emulsions were investigated, and the results revealed that the interface of the emulsions prepared by the new method contained all major MFGM proteins and unique GO annotations and KEGG pathways. However, only four MFGM proteins (XO, ADPH, PAS 6/7) were quantified at the interface of the emulsions prepared by the common method. Furthermore, the protein number and the total relative abundance of major MFGM proteins were approximately 2-fold and 475-fold higher at the interface of the emulsions prepared by the new method compared to the common method. Overall, the study modulated the interfacial protein composition of fat globules by screening the sources of lipid and homogenization methods and revealed its potential effect on processing stability and biological properties.

Insights from 4D Label-Free Proteomic Analysis into Variation of Milk Fat Globule Membrane Proteins of Human Milk Associated with Infant's Gender

Milk fat globule membrane (MFGM) protein profiles of breast milk collected from women in northeast China with male or female babies were investigated using a four-dimensional (4D) label-free proteomic technique. Altogether, 2538 proteins were detected and quantified and 249 were differentially expressed, with 198 decreased proteins compared to the samples of mothers with female babies. Different proteins associated with infant's gender were principally located in nuclear. The differentially expressed proteins were mainly involved in gene ontology (GO) functions of the cellular process, binding, and cell and found to be distributed in lipid-related biological processes and molecular functions to a large extent. The pathway of neurodegeneration-multiple disease ranked top for the altered proteins. The screened proteins were observed to contain some proteins related to typical functions of immunity, lipid metabolism, digestion, and growth and development. 114 proteins formed a relatively compact network (269 interactions) and dolichyl-diphospho-oligosaccharide-protein glycosyltransferase subunit 2 interacted the most with other proteins as the hub protein. MFGM proteins of breast milk were affected by the sex of offspring, and these findings may provide useful information for reasonable adjustments of infant formula powder specifically for boys or girls in the market.

Comparative Label-Free Liquid Chromatography-Mass Spectrometry Milk Proteomic Profiles Highlight Putative Differences between the Autochthon Teramana and Saanen Goat Breeds

Goat's milk is an excellent source of nutrients, with greater benefits compared to cow's milk. Limited information is available on autochthon goat breeds, which are important for biodiversity preservation. In this study, the aim of using label-free quantification was to investigate the milk proteome of two goat breeds, the autochthon Teramana and Saanen breeds, which are commonly used by the industry. Utilising label-free proteomic analysis, 749 and 666 proteins, respectively were identified and quantified from the Teramana and Saanen goat milk. Moreover, utilising statistical analysis, 29 proteins were able to discriminate the two goat breeds, with many of the identified proteins involved in complement and coagulation cascades. This work enhances our understanding of the goat milk proteome and shows differences between the two breeds, leading to an important contribution toward a more detailed molecular-view of this unique substrate. Additionally, charactersation of the milk proteins can help in guiding genetic improvements in the goat herds, and thus increasing its use in human nutrition.

Label-free quantitative proteomic analysis of milk fat globule membrane proteins in porcine colostrum and mature milk

Milk fat globule membrane (MFGM) proteins are nutritional components with various biological functions. This study aimed to analyze and compare MFGM proteins in porcine colostrum (PC) and porcine mature milk (PM), via label-free quantitative proteomics. In total, 3917 and 3966 MFGM proteins were identified in PC and PM milk, respectively. A total of 3807 common MFGM proteins were found in both groups, including 303 significant differentially expressed MFGM proteins. Gene Ontology (GO) analysis revealed that the differentially expressed MFGM proteins were mainly related to the cellular process, cell, and binding. The dominant pathway of the differentially expressed MFGM proteins was related to the phagosome according to Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. These results reveal crucial insights into the functional diversity of MFGM proteins in porcine milk during lactation and provide theoretical guidance for the development of MFGM proteins in the future.

Infant formulae - Key components, nutritional value, and new perspectives

Breastfeeding is the most effective strategy for meeting the nutritional demands of infants, whilst infant formulae are manufactured foods that mimic human milk and can be safely used to replace breastfeeding. In this paper, the compositional differences between human milk and other mammalian milk are reviewed, and thus nutritional profiles and compositions of standard bovine milk-based formulae as well as special formulae are discussed. Differences between breast milk and other mammalian milk in composition and content affect their digestion and absorption in infants. Characteristics and mimicking of breast milk have been intensively studied with the objective of narrowing the gap between human milk and infant formulae. The functions of the key nutritional components in infant formulae are examined. This review detailed recent developments in the formulation of different types of special infant formulae and efforts for their humanization, and summarized safety and quality control of infant formulae.

Nanosecond pulsed electric field treatment of human milk: Effects on microbiological inactivation, whey proteome and bioactive protein

In the current study, nanosecond pulsed electric field (nsPEF) was investigated at lab-scale to optimise processing conditions of donor human milk to reduce bacterial counts, and to evaluate its effect on the bioactive proteins in human milk. Response surface methodology was utilized to optimise critical processing parameters. Two optimal nsPEF processing conditions were validated: 15 kV voltage, 6000 pulses at 20 Hz frequency, and 15 kV voltage, 6000 pulses at 50 Hz frequency. Compared to raw human milk, nsPEF processed milk had over 60 % retention of lysozyme, lactoperoxidase and lactoferrin, and 100 % retention of xanthine oxidase and immunoglobulin A. The contents of the five proteins were significantly higher after nsPEF processing when compared with Holder pasteurization. Liquid chromatography-mass spectrometry analysis showed that loss of milk proteins was smaller for samples treated with nsPEF than Holder pasteurization. These results indicated that nsPEF is a promising novel pasteurization method.

Proteomic characterization and comparison of milk fat globule membrane proteins of Saanen goat milk from 3 habitats in China using SWATH-MS technique

Saanen goats are among the major dairy goats in China. In present study, variation of milk fat globule membrane proteins profile of Saanen goat milk caused by geographic location was investigated using sequential window acquisition of all theoretical fragment ions data-independent acquisition mass spectrometry based proteomic approach. A total of 1,001 proteins were quantified in goat milk collected from 3 habitats of China [Guangdong (GD); Inner Mongolia (IM); Shannxi (SX)]. Most of the proteins were found to act cellular process of biological process, cell of cellular component, binding of molecular function after Gene Ontology annotation and metabolic of pathway indicated by Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. Differentially expressed proteins (DEP) for GD versus IM, GD versus SX, IM versus SX were identified to be 81, 91, and 44, respectively. Gene Ontology enrichment analysis showed that the greatest DEP for 3 groups (GD vs. IM, GD vs. SX, IM vs. SX) were cellular process, cellular process and organonitrogen compound biosynthetic process/immune system process for biological process. For cellular component, the largest number of DEP for 3 comparison groups were organelle, organelle and organelle/intracellular. For molecular function, DEP of the 3 comparison groups were expressed most in structural molecule activity, binding and anion binding, respectively. Pathways with the majority of DEP were ribosome, systemic lupus erythematosus and primary immunodeficiency/systemic lupus erythematosus/amoebiasis/PI3K-Akt signaling pathway for GD versus IM, GD versus SX and IM versus SX, severally. Protein-protein interaction network analysis showed that DEP interacted most were 40S ribosomal protein S5, fibronectin and Cytochrome b-c1 complex subunit 2, mitochondrial for GD versus IM, GD versus SX and IM versus SX, separately. Data may give useful information for goat milk selection and milk authenticity in China.

Traditional Chinese medicine prescription Shenling BaiZhu powder to treat ulcerative colitis: Clinical evidence and potential mechanisms

Ulcerative colitis (UC), characterized by syndromes including abdominal pain, bloody stool, diarrhea, weight loss, and repeated relapse, is a non-specific inflammatory intestinal disease. In recent years, with the changing dietary habits in China, the incidence of UC has shown an upward trend. UC belongs to the category of recorded as “diarrhea,” “chronic dysentery,” and “hematochezia” in traditional Chinese medicine (TCM), and Shenling BaiZhu powder (SLBZP) is one of the most effective and commonly used prescriptions. In this review, we aim to systematically summarize the clinical application and pharmacological mechanism of SLBZP in the treatment of UC to provide a theoretical basis for its clinical use and experimental evaluation of SLBZP. Our results showed that both SLBZP and SLBZP in combination with chemical drugs, have a significant therapeutic effect against UC with few adverse reactions. Furthermore, combined therapy was better than western medicine. Further, pathophysiological studies indicated that SLBZP has anti-inflammatory, immunomodulatory, antioxidant effects, regulation relative cell signal transduction and regulation of gut microbiota. Although evidence suggests superior therapeutic efficacy of SLBZP for treating UC and the relative mechanism has been studied extensively, various shortcomings limit the existing research on the topic. There is a lack of UC animal models, especially UC with TCM syndromes, with no uniform standard and certain differences between the animal model and clinical syndrome. The dosage, dosage form, and therapeutic time of SLBZP are inconsistent and lack pharmacological verification, and clinical trial data are not detailed or sufficiently rigorous. In addition, SLSZP is composed of multiple Chinese drugs that contain massive numbers of ingredients and which or several components contribute to therapeutic effects. How they work synergistically together remains unknown. Therefore, on the one hand, large sample prospective cohort studies to clarify the clinical efficacy and safety of SLBZP in the treatment of UC are needed. In contrast, researchers should strengthen the study of the molecular biological mechanism of active ingredients and its synergistic actions, clarifying the mechanism of SLBZP in treating UC by multi-component, multi-target, and multi-pathway.

Changes in Caprine Milk Fat Globule Membrane Proteins after Heat Treatment Using a Label-Free Proteomics Technique

Milk proteins are prone to changes during the heat treatment process. Here, we aimed to study the changes in caprine milk fat globule membrane (MFGM) proteins with three heat treatment processes—ultra-pasteurization (85 °C, 30 min), ultra-high-temperature instant sterilization (135 °C, 5 s), and spray-drying (inlet, 160 °C and outlet, 80 °C)—using the label-free proteomics technique. A total of 1015, 637, 508, and 738 proteins were identified in the raw milk, ultra-pasteurized milk, ultra-high-temperature instant sterilized milk, and spray-dried reconstituted milk by using label-free proteomics techniques, respectively. Heat treatment resulted in a significant decrease in the relative intensity of MFGM proteins, such as xanthine dehydrogenase/oxidase, butyrophilin subfamily 1 member A, stomatin, and SEA domain-containing protein, which mainly come from the membrane, while the proteins in skimmed milk, such as β-lactoglobulin, casein, and osteopontin, increased in MFGM after heat treatment. Among these different heat treatment groups, the procedure of spray-drying resulted in the least abundance reduction of caprine milk MFGM proteins. Additionally, it showed heating is the key process affecting the stability of caprine MFGM protein rather than the spray-drying process. These findings provide new insights into the effects of heat treatment on caprine MFGM protein composition and potential biological functions.

Soybean-Oil-Body-Substituted Low-Fat Ice Cream with Different Homogenization Pressure, Pasteurization Condition, and Process Sequence: Physicochemical Properties, Texture, and Storage Stability

The purpose of this research was to explore the impacts of different homogenization pressures, pasteurization conditions, and process sequence on the physical and chemical properties of soybean oil body (SOB)-substituted low-fat ice cream as well as the storage stability of SOB-substituted ice cream under these process parameters. With the increase of homogenization pressure (10–30 MPa), the increase of pasteurization temperature (65 °C for 30 min–85 °C for 15 min), and the addition of SOB before homogenization, the overrun and apparent viscosity of ice cream increased significantly, and the particle size, hardness, and melting rate decreased significantly. Thus, frozen dairy products of desired quality and condition could be obtained by optimizing process parameters. In addition, the SOB ice cream showed better storage stability, which was reflected in lower melting rate and hardness and more stable microstructure compared with the full-milk-fat ice cream. This study opened up new ideas for the application of SOB and the development of nutritious and healthy ice cream. Meanwhile, this research supplied a conceptual basis for the processing and quality optimization of SOB ice cream.

First Insight into the Variation of the Milk Serum Proteome within and between Individual Cows

Milk contains all nutrients needed for development of calves. One important group of components responsible for this are the milk proteins. Variation due to feed or animal health, has been studied for the most abundant milk proteins. The aim of this study was to determine the variation between and within cows for their milk serum proteome. Sample Set 1 was collected from Holstein Friesian (HF) cows between November 2011 and March 2012 and prepared using filter aided sample preparation (FASP) followed by LC-MS/MS for protein identification and quantification. The results showed that the milk serum proteome was very constant in mid lactation (four cows at five time points, p > 0.05) between 3 and 6 months in lactation. Sample Set 2 was collected from HF cows in Dec 2012 and analyzed using FASP and dimethyl labeling followed by LC-MS/MS. Significant variation in the milk serum proteome (p < 0.05) between 17 individual cows was found in Sample Set 2. The most variable proteins were immune-related proteins, which may reflect the health status of the individual cow. On the other hand, proteins related to nutrient synthesis and transport were relatively constant, indicating the importance of milk in providing a stable supply of nutrients to the neonate. In conclusion, the milk serum proteome was stable over mid lactation, but differed significantly between individuals, especially in immune-related proteins.

Intestinal Dysbiosis in the Infant and the Future of Lacto-Engineering to Shape the Developing Intestinal Microbiome

PURPOSE

The goal of this study was to review the role of human milk in shaping the infant intestinal microbiota and the potential of human milk bioactive molecules to reverse trends of increasing intestinal dysbiosis and dysbiosis-associated diseases.

METHODS

This narrative review was based on recent and historic literature.

FINDINGS

Human milk immunoglobulins, oligosaccharides, lactoferrin, lysozyme, milk fat globule membranes, and bile salt-stimulating lipase are complex multifunctional bioactive molecules that, among other important functions, shape the composition of the infant intestinal microbiota.

IMPLICATIONS

The co-evolution of human milk components and human milk-consuming commensal anaerobes many thousands of years ago resulted in a stable low-diversity infant microbiota. Over the past century, the introduction of antibiotics and modern hygiene practices plus changes in the care of newborns have led to significant alterations in the intestinal microbiota, with associated increases in risk of dysbiosis-associated disease. A better understanding of mechanisms by which human milk shapes the intestinal microbiota of the infant during a vulnerable period of development of the immune system is needed to alter the current trajectory and decrease intestinal dysbiosis and associated diseases.

Quantification of FAM20A in human milk and identification of calcium metabolism proteins

BACKGROUND

FAM20A, a recently discovered protein, is thought to have a fundamental role in inhibiting ectopic calcification. Several studies have demonstrated that variants of FAM20A are causative for the rare autosomal recessive disorder, enamel-renal syndrome (ERS). ERS is characterized by defective mineralization of dental enamel and nephrocalcinosis suggesting that FAM20A is an extracellular matrix protein, dysfunction of which causes calcification of the secretory epithelial tissues. FAM20A is a low-abundant protein that is difficult to detect in biofluids such as blood, saliva, and urine. Thus, we speculated the abundance of FAM20A to be high in human milk, since the secretory epithelium of lactating mammary tissue is involved in the secretion of highly concentrated calcium. Therefore, the primary aim of this research is to describe the processes/methodology taken to quantify FAM20A in human milk and identify other proteins involved in calcium metabolism.

METHOD

This study used mass spectrometry-driven quantitative proteomics: (1) to quantify FAM20A in human milk of three women and (2) to identify proteins associated with calcium regulation by bioinformatic analyses on whole and milk fat globule membrane fractions.

RESULTS

Shotgun MS/MS driven proteomics identified FAM20A in whole milk, and subsequent analysis using targeted proteomics also successfully quantified FAM20A in all samples. Combination of sample preparation, fractionation, and LC-MS/MS proteomics analysis generated 136 proteins previously undiscovered in human milk; 21 of these appear to be associated with calcium metabolism.

CONCLUSION

Using mass spectrometry-driven proteomics, we successfully quantified FAM20A from transitional to mature milk and obtained a list of proteins involved in calcium metabolism. Furthermore, we show the value of using a combination of both shotgun and targeted driven proteomics for the identification of this low abundant protein in human milk.

Influence of ultrasound application on the microbiota of raw goat milk and some food pathogens including Brucella melitensis

The aim of the present study was to investigate the detrimental effect of ultrasound application, as an alternative to pasteurization, on raw goat milk microorganisms and some food pathogens including Brucella melitensis. For this purpose, six different ultrasound applications with a power of 20 kHz at 100%, 50% and 10% amplitudes with or without pulsation were practiced. Colour changes as an increase in brightness (L-value) and decrease in yellow colour value (b-value) were determined in either pasteurized or ultrasonified groups. The most efficient detrimental effect on bacteria was obtained at 100% amplitudes (III and IV group). In these groups, decrease of TAMB, coliforms, streptococci, lactobacilli, yeast and mould counts were 6.52, 6.27, 5.31, 5.61, 5.27 and 4.02 log cfu/ml respectively in raw milk. Inactivation of food pathogens Brucella melitensis type 3, Salmonella Typhimirium, Escherichia coli, Listeria monocytogenes and methicilin resistant Staphylococcus aureus inoculated in goat milk was approximately 99%, which was as efficient as HTST and LTLT pasteurization process. Consequently, ultrasound applications can be an alternative to heat processes in dairy since effective bacterial inactivation could be attained in a relatively economic and environmentally friendly way.

Quantitative analysis of differentially expressed milk fat globule membrane proteins between donkey and bovine colostrum based on high-performance liquid chromatography with tandem mass spectrometry proteomics

This study was designed to provide novel insights into milk fat globule membrane (MFGM) proteins in donkey colostrum (DC) and bovine colostrum (BC) using quantitative proteomics. In total, 179 (DC) and 195 (BC) MFGM proteins were characterized, including 71 shared, 108 DC-specific, and 124 BC-specific proteins. Fifty-one shared proteins were selected as differentially expressed MFGM proteins, including 21 upregulated and 30 downregulated proteins in DC. Gene ontology analysis showed that these proteins were mainly enriched in cellular components, including the extracellular exosome, extracellular space, and plasma membrane. Additionally, they were further involved in metabolic pathways, including cholesterol metabolism, the peroxisome proliferator-activated receptor signaling pathway, and purine metabolism. Furthermore, several key protein factors with high connectivity were identified via protein-protein interaction analysis. These results provide more comprehensive knowledge of differences in the biological properties of MFGM proteins in DC and BC as well as pave the way for future studies of the nutritional and functional requirements of these important ingredients toward the development of dairy products based on multiple milk sources.

Dairy Processing Affects the Gut Digestion and Microecology by Changing the Structure and Composition of Milk Fat Globules

Milk fat globules (MFGs) are the major source of energy for infants' dietary intake. In this study, the effects of changes in the structure and composition of MFG after dairy processing on lipolysis and immune regulation were investigated. Pasteurized MFG tends to form protein aggregates to prevent lipolysis. However, the aggregate is rich in neutrophil degranulation products, which are effective in killing pathogens. Homogenized MFG has the lowest hydrolysis rate due to the reconstituted anti-lipase barrier and exposed apolipoprotein. Simultaneously, the reconstituted barrier can compensate for the lack of the complement cascade. Spray-dried MFG had the highest hydrolysis rate attributable to the disrupted MFG barrier and the release of lipoprotein lipase and endothelial lipase. The immunomodulatory properties of spray-dried MFG proteins are mainly mediated by the toll-like receptor (TLR) signaling pathway. This research provides the improvement basis of dairy processing and functional infant formulas.

Effects of Human, Caprine, and Bovine Milk Fat Globules on Microbiota Adhesion and Gut Microecology

Milk fat is an essential nutrient for infant development. The effects and mechanisms of human, caprine, and bovine milk fat globules (MFGs) on the gut microbiota were investigated in this study. Human MFGs enhance the efficacy of probiotics by inhibiting pathogen function. Akkermansia and Bifidobacterium were identified as the dominant microbiota by human MFGs. Mucin and complement inhibitory proteins in human MFGs were found to inhibit different pathogens. Caprine MFGs directly promoted the colonization of probiotics and the emergence of the biomarker Allobaculum. Mucin 1 in caprine MFGs was primarily responsible for inducing probiotic adhesion. Bovine MFGs increased the abundance of Oscillospira, which reduces the risk of obesity. Due to the enrichment of cell-cell junction proteins and the lack of mucin, the regulation of gut microecology by bovine MFGs was not readily apparent. In short, this study paves the way for the development of functional infant formula.

Comparison of milk fat globule membrane and whey proteome between Dromedary and Bactrian camel

Camel milk is rich in nutrients and its impact on human medicine and nutrition cannot be ignored. We conducted an in-depth analysis of milk proteins obtained from two camel breed (Camelus bactrianus, CB and Camelus dromedarius, CD). Label-free proteomic technology was performed to analysis the MFGM and whey proteomes of CB and CD milk. In total, 1133 MFGM proteins and 627 whey proteins were identified from camel milk. Results revealed that 216 MFGM proteins and 109 whey proteins were significantly different between them. In addition, the cellular process, cell and binding were the predominately GO annotations of milk proteins. KEGG analysis shown that most proteins were involved in metabolic pathways. Furthermore, many proteins were found to be involved in PI3K/AKT signaling pathway, which could be the possible reason for hypoglycemic effect of camel milk. These results could provide a further understanding for unique biological characteristics of camel milk proteins.

Ruminant Milk-Derived Extracellular Vesicles: A Nutritional and Therapeutic Opportunity?

Milk has been shown to contain a specific fraction of extracellular particles that are reported to resist digestion and are purposefully packaged with lipids, proteins, and nucleic acids to exert specific biological effects. These findings suggest that these particles may have a role in the quality of infant nutrition, particularly in the early phase of life when many of the foundations of an infant's potential for health and overall wellness are established. However, much of the current research focuses on human or cow milk only, and there is a knowledge gap in how milk from other species, which may be more commonly consumed in different regions, could also have these reported biological effects. Our review provides a summary of the studies into the extracellular particle fraction of milk from a wider range of ruminants and pseudo-ruminants, focusing on how this fraction is isolated and characterised, the stability and uptake of the fraction, and the reported biological effects of these fractions in a range of model systems. As the individual composition of milk from different species is known to differ, we propose that the extracellular particle fraction of milk from non-traditional and minority species may also have important and distinct biological properties that warrant further study.

Distribution and variation in proteins of casein micellar fractions response to heat-treatment from five dairy species

Casein micelles (CMs) contribute to the physicochemical properties and stability of milk. However, how the proteome of CMs changes following heat treatment has not been elucidated. Here, changes in the proteins of CMs in samples of Holstein, buffalo, yak, goat, and camel milk following heat treatment were investigated using a LC-MS/MS approach. According to the hierarchical clustering results, Holstein, yak, and buffalo milk samples had similar CMs protein components, followed by goat and camel milk samples. Changes in lipoprotein lipase and α-lactalbumin in CMs were dependent on the intensity of heat treatment and were similar among the studied species, whereas changes in κ-casein, lactoferrin, and apolipoprotein A-I differed among different types of milk. These results provide information on the distribution and variations of the proteomes of CMs following heat treatment, which will assist in the identification of proteins that are dissociated and attached to CMs from different dairy species during heat treatment.

Quality of Set Yogurts Made from Raw Milk and Processed Milk Supplemented with Enriched Milk Fat Globule Membrane in a Two-Stage Homogenization Process

Dairy products are relevant in the food industries as functional ingredients for several food products and contribute towards human nutrition in ameliorating certain disorders. In this study, set yogurts were produced from raw milk and processed milk combined with 4% Lacprodan®PL20 concentration and subjected to two-stage pressure homogenization. The total solids concentration of the mixture was raised to 15% using SMP (skim milk powder). The purpose of this study was to investigate the effect of Lacprodan®PL20 on the set yogurt quality produced by homogenization-induced pressure and its interaction with milk components. The changes in the physical and chemical attributes of the milk fat globule membrane (MFGM) via destabilization of the membrane significantly affected the physicochemical properties of set yogurts produced from processed or raw milk. There was a slight variation in MFGM-specific proteins detected in the set yogurts. Set yogurt produced from homogenized raw milk (HRM) had a considerably higher water-holding capacity, firmness, and apparent viscosity. The microstructure of HRM was dense and compacted, unlike non-homogenized raw milk (NRM) with large MFGM fragments and pore holes between the matrixes. The inclusion of homogenization showed a remarkable improvement in set yogurt quality, promoting interaction between MFGM components and milk proteins.

Effects of dairy processing on phospholipidome, in-vitro digestion and Caco-2 cellular uptake of bovine milk

Present work investigated the effects of processing (homogenization, sterilization) and cold storage on physicochemical properties, in vitro digestion and Caco-2 cellular uptake of bovine milk. Extreme heat sterilization and low temperature storage have significant impact on particle size and phospholipidome of bovine milk. In addition, cold storage of bovine milks led to formation of β' polymorphs crystals and endothermic peak with T_offset higher than body temperature. Processing and cold storage also increased the initial digestibility but reduced the overall digestibility of bovine milk. This might be related to the decreased particle size of the milk fat globules, changed in the phospholipidome of the MFGM and formation of β' polymorphs crystals in frozen milk. It is interesting to note that PE has relatively faster digestion meanwhile SM has relatively slower digestion. HTST milk which demonstrated lesser changed in terms of phospholipidome demonstrated highest cellular uptakes of most fatty acids.

Novel insights into whey protein differences between donkey and bovine milk

In this study, we characterized and compared the whey proteins from donkey and bovine milk using HPLC-MS/MS-based proteomics. A total of 989 and 1534 whey proteins were characterized in donkey and bovine milk, respectively. Furthermore, 623 whey proteins were found in both groups, and 229 differentially expressed whey proteins (DEWPs) were identified. Among the common proteins, 66 DEWPs were upregulated and 163 were downregulated in donkey milk compared to those in bovine milk. Gene Ontology analysis revealed the cellular components, biological processes, and molecular functions of these DEWPs. Metabolic pathway analysis suggested that most DEWPs were associated with endocytosis, platelet activation, and phagocytosis. These results improve our understanding of the differences between donkey and bovine whey proteins and provide important information regarding these proteins as nutritional and functional factors in dairy product formulations from multiple milk sources.

Human milk proteome: what's new?

PURPOSE OF REVIEW

The proteome is one of the most complicated and multifunctional components in human milk. Recently, numerous novel characteristics of the human milk proteome have been discovered, which are described and critically examined in this review.

RECENT FINDINGS

Recent human milk proteomics studies have focused on how external factors like geography and environment, or maternal and infant's factors affect the milk proteins, endogenous peptides, their posttransitional modifications (PTMs) and infant utilization. Most of these studies have shown that major protein and endogenous peptide profiles are similar for healthy women and infants. The human milk proteome has been expanded by providing novel insights into PTMs like glycosylation and phosphorylation, and how the proteins and peptides are digested and utilized by the infant. All human milk proteomics studies are subject to conditions in which the samples were collected, handled and stored.

SUMMARY

Significant technological advancements in mass spectrometry have considerably enabled a deeper and more comprehensive identification and characterization of the expanded human milk proteome. However, data concerning human milk from mothers with infections or illnesses and mothers nursing more vulnerable infants are still limited and the roles of the components of the human milk proteome have not yet been sufficiently elucidated.

Changes in bioactive proteins and serum proteome of human milk under different frozen storage

This study aimed to investigate changes in macronutrients, total bacterial count, and serum proteome of human milk (HM) under different frozen storage (-18°C and -60°C, 60 d and 180 d) by using IBT Labeling proteomics techniques and ELISA kit. The results indicated that total protein concentrations and total aerobic bacterial counts were significantly decreased at -18°C, while no difference at -60°C. A total of 1617 proteins were identified and quantified, and 173 proteins were significantly different. The -18°C storage had much higher influence on HM serum protein profiles than that of -60°C. Increased milk fat globule membrane (MFGM) proteins at -18°C are highly related to the damage of MFGM and transfer of MFGM proteins. The reduction of bioactive proteins is probably related to the ice-induced denaturation. In conclusion, fast cooling and ultra-low constant temperature are more suitable for the cryopreservation of human milk.

Improving Human Health with Milk Fat Globule Membrane, Lactic Acid Bacteria, and Bifidobacteria

The milk fat globule membrane (MFGM), the component that surrounds fat globules in milk, and its constituents have gained significant attention for their gut function, immune-boosting properties, and cognitive-development roles. The MFGM can directly interact with probiotic bacteria, such as bifidobacteria and lactic acid bacteria (LAB), through interactions with bacterial surface proteins. With these interactions in mind, increasing evidence supports a synergistic effect between MFGM and probiotics to benefit human health at all ages. This important synergy affects the survival and adhesion of probiotic bacteria through gastrointestinal transit, mucosal immunity, and neurocognitive behavior in developing infants. In this review, we highlight the current understanding of the co-supplementation of MFGM and probiotics with a specific emphasis on their interactions and colocalization in dairy foods, supporting in vivo and clinical evidence, and current and future potential applications.