Fat Globule Membrane Phospholipids Research Articles

Milk fat globule membrane (MFGM) phospholipid - Whey protein interaction characterization and its effect on physicochemical, interfacial properties and evaluation of in vitro digestion of emulsions - Inspired by the MFGM

The interfacial composition of fat globules can change the interfacial structure and further affect the digestive characteristics. In this study, the interaction between whey protein (WP), which is the main protein added in infant formula (IF), and milk fat globule membrane phospholipid (MPL) was investigated from the perspective of simulated fat globule structure, we further characterized the physicochemical properties and the in vitro digestive performance of the emulsions. The results showed that the interaction between MPL and WP changed the secondary and tertiary structures of WP, and formed a dense protective layer at the interface of the fat globule with strong interaction, which improved the emulsification property and physical stability of the emulsion. When MPL: WP was 5:10, the emulsions showed smaller particle size, higher absolute value of zeta-potential and more uniform and stable emulsion state. In addition, during the simulated in vitro digestion of infants, the degree of lipolysis and free fatty acid release content were significantly increased, which improved the fat digestion.

Proteosomes based on milk phospholipids and proteins to enhance the stability and bioaccessibility of β-carotene.

Proteosomes (P) based on milk fat globule membrane's phospholipids (MPs), whey protein isolate (WPI) and sodium caseinate (CasNa) were developed by ultrasonication to encapsulate β-carotene. Entirely milk-ingredients based proteosomes (WPI-MPs-P and CasNa-MPs-P) revealed homogenous distribution with size diameters<250nm. WPI-MPs-P depicted positive ζ-potential values (+15.7±0.5mV), while CasNa-MPs-P demonstrated negative (-32.5±3.4mV) values of surface charge, respectively and hydrophilic nature of proteosomes was observed by measuring contact-angle (θ). AFM and SEM exhibited spherical to oval and slightly irregular morphology of nanocarriers. For various concentrations of β-carotene, the highest encapsulation efficiency of β-carotene was 90±0.2% and 92±0.8% in WPI-MPs-P and CasNa-MPs-P respectively. FTIR analyses confirmed the hydrophobic and electrostatic interactions-based encapsulation of β-carotene. Beneficial antioxidant-potential of β-carotene was retained after its encapsulation in the proteosomes. Proteosomes increased the digestive-stability (>50%) and bioaccessibility (>85%) of β-carotene. Thus, milk-ingredients based proteosomes offer a novel-strategy to develop functional dairy products to overcome widespread vitamin-A-deficiency.

Potential of milk fat globule membrane's phospholipids and anhydrous milk fat based nanostructured lipid carriers for enhanced bioaccessibility of vitamin D3

Novel nanostructured lipid carriers (NLCs) were engineered using anhydrous milk fat (AMF) as vitamin-D3 (VD3) carrier and milk fat globule membrane (MFGM) phospholipids (PLs) as surfactants. Significantly higher encapsulation efficiency of VD3 was obtained (96 ± 2.5%) in AMF-MFGM-PLs NLCs. Void and VD3 loaded NLCs had diameters of 150 ± 0.2 nm and 167 ± 2 nm and ζ-potentials of −15.5 ± 1.6 mV and −15.9 ± 0.3 mV, respectively. NLCs had spherical morphology; VD3 was distributed in the lipid core of NLCs via weak electrostatic or hydrophobic interactions. Physical stability in terms of particle size and homogeneity of particles was attained for a three-week storage period. Biphasic in-vitro controlled release kinetics was observed, i.e., burst release followed by sustained release up to 21 days. VD3 exhibited effective chemical stability (48.3 ± 3.4%) and significantly higher bioaccessibility (88 ± 2.6%) after complete simulated in-vitro digestion. VD3 loaded NLCs are promising natural vehicles for the effective delivery of less-bioaccessible vitamins to overcome micronutrient deficiency.

The influence of MPL addition on structure, interfacial compositions and physicochemical properties on infant formula fat globules

The lack of milk fat globule membrane phospholipids (MPL) at the interface of infant formula fat globules has an impact on the stability of fat globules, compared to human milk. Therefore, infant formula powders with different MPL contents (0%, 10%, 20%, 40%, 80%, w/w of MPL/whey protein mixture) were prepared, and the effect of interfacial compositions on the stability of globules was investigated. With increasing MPL amount, the particle size distribution had two peaks and returned to a uniform state when 80% MPL was added. At this composition, the MPL at the oil–water interface formed a continuous thin layer. Moreover, the addition of MPL improved the electronegativity and the emulsion stability. In terms of the rheological properties, increasing the concentration of MPL improved the elastic properties of the emulsion and the physical stability of the fat globules, while reducing the aggregation and agglomeration between fat globules. However, the potential for oxidation increased. Based on these results, the interfacial properties and stability on infant formula fat globules was significantly influenced by the level of MPL, which should be considered in the design of infant milk powders.

Heat-stable liposomes from milk fat globule membrane phospholipids for pH-triggered delivery of hydrophilic and lipophilic bioactives

Heat-stable, multivitamin-loaded, and surface-coated liposomes tailored for pH-triggered delivery of both lipophilic and hydrophilic bioactives were synthesized from a cocktail of milk fat globule membrane (MFGM) phospholipids, supercritically extracted from buttermilk powder. Liposomes from MFGM-phospholipids (ML) were fabricated using a novel organic solvent free process based on venturi-based rapid expansion of a supercritical solution. A commercially available pH-responsive polymer, Eudragit® S100 was used to coat ML (Eu-ML). Eu-MLs were heated to 60, 75, and 90 °C for 30 min and were observed to be heat-stable as established by CLSM images, structural characterizations, and encapsulation efficiency measurements. Coating of liposomes with Eudragit® S100 protected encapsulated payload from deleterious gastric environment and facilitated site-specific pH-triggered release in the simulated intestinal condition. This study established a green method to fabricate heat-stable liposomal vehicles for pH-triggered delivery of bioactive compounds with excellent potential for scale-up and applications in the food, pharmaceutical, and cosmetic industries.

Milk fat globule membrane phospholipids modify adhesion of Lactobacillus to mucus-producing Caco-2/Goblet cells by altering the cell envelope

The importance of various Lactobacillus strains and milk components, such as the milk fat globule membrane, has been studied from various perspectives and proven to have a positive role in human health. On one end, lactic acid bacteria produce metabolites with direct effect in the immune system, changes of pH in the gut, and antagonistic substances for pathogenic bacteria as well as competition. On the other end, the milk fat globule membrane improves gastrointestinal status by promoting cell proliferation, epithelial tight junction patterns, and development of intestinal epithelial cells. Interaction between beneficial bacteria and milk fat is a natural occurring phenomenon in dairy products; however, it has not been fully characterized. In this work, we studied the effect of milk phospholipids in the adhesion of Lactobacillus to mucus-producing Caco-2/Goblet cell co-cultures and found that treatment with phospholipids produced bacterial cells with increased surface electronegativity, which was correlated with increased bacterial cells adhered to the intestinal model. Moreover, we utilized an original means of characterizing the adhesion using quartz crystal microbalance. All strains studied, experienced modification of adhesion either physicochemical or kinetic parameters studied. Furthermore, by imaging bacterial cells by electron microscopy, we identified that some strains, such as L. acidophillus and L. casei, metabolized MPL, which improved their adhesion to hydrophilic surfaces such as gold. We identified another group of bacteria, such as L. delbrueckii and L. plantarum, that, instead of metabolizing MPL, kept the phospholipids bound irreversibly to the surface of the cell envelope thus decreasing their adherence to gold surfaces. One of the most important aspects of probiotic lactic acid bacteria —besides survival in the stomach—is the colonization and extended resident time in the intestine to effectively change the gut microbiome. We found that bacterial treatment with milk phospholipids enhances adhesion to intestinal models and will in turn, increase the residence time with the concomitant benefits to the consumer.

Effect of Particle Size and Interface Composition on the Lipid Digestion of Droplets Covered with Membrane Phospholipids

The particle size and fatty acid release of droplets covered with milk fat globule membrane phospholipids with different particle sizes (large/MPL-L; medium/MPL-M; and small/MPL-S) and emulsions with different sources (droplets covered with MPL/MPLs; human milk/HM; and infant formula/IF) were investigated using an infant digestion model. During digestion, droplets exhibited different degrees of aggregation, and the order of the particle size was MPL-L > MPL-M > MPL-S. MPL-M and MPL-S were significantly higher than MPL-L in the release of free fatty acids. No significant difference was observed in the FFA release rate between MPLs and HM. However, the rate was significantly higher than that of IF in the intestinal stage. Compared to IF, a higher content of long-chain polyunsaturated fatty acids and a lower content of saturated fatty acid were observed in MPLs and HM.

Arachidonic Acid in Human Milk.

Breastfeeding is universally recommended as the optimal choice of infant feeding and consequently human milk has been extensively investigated to unravel its unique nutrient profile. The human milk lipid composition is unique and supplies specifically long-chain polyunsaturated fatty acids (LC-PUFAs), in particular, arachidonic acid (ARA, 20:4n–6) and docosahexaenoic acid (DHA, 22:6n–3). Arachidonic acid (ARA) is the most predominant long-chain polyunsaturated fatty acid in human milk, albeit at low concentrations as compared to other fatty acids. It occurs predominantly in the triglyceride form and to a lesser extent as milk fat globule membrane phospholipids. Human milk ARA levels are modulated by dietary intake as demonstrated by animal and human studies and consequently vary dependent on dietary habits among mothers and regions across the globe. ARA serves as a precursor to eicosanoids and endocannabinoids that also occur in human milk. A review of scientific and clinical studies reveals that ARA plays an important role in physiological development and its related functions during early life nutrition. Therefore, ARA is an important nutrient during infancy and childhood and, as such, appropriate attention is required regarding its nutritional status and presence in the infant diet. Data are emerging indicating considerable genetic variation in encoding for desaturases and other essential fatty acid metabolic enzymes that may influence the ARA level as well as other LC-PUFAs. Human milk from well-nourished mothers has adequate levels of both ARA and DHA to support nutritional and developmental needs of infants. In case breastfeeding is not possible and infant formula is being fed, experts recommend that both ARA and DHA are added at levels present in human milk.

Synthesis of multivitamin-loaded heat stable liposomes from milk fat globule membrane phospholipids by using a supercritical-CO2based system

Inspired by the heat stability of milk, where fat globules are coated by the milk fat globule membrane (MFGM), heat stable liposomes loaded with multivitamins were successfully synthesized from MFGM phospholipid concentrate.

Impact of technological processes on buffalo and bovine milk fat crystallization behavior and milk fat globule membrane phospholipids profile

The effects of milk technological processes (pasteurization, homogenization, and freeze-drying) on the crystallization and melting behaviors of buffalo and bovine milk fat were investigated. As well, the profile of milk phospholipids was identified. Differential scanning calorimetry was used to evaluate the variations in the thermal behaviors of milk fat. Milk phospholipids were purified by the solid-phase extraction method, and then identified by using an ultra-performance liquid chromatography-electrospray ionization-quadrupole-time of flight-mass spectrometry. Seven classes of phospholipids (including phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, phosphatidylserine, phosphatidylglycerol, sphingomyelin, and lysophosphatidylcholine) were identified. Milk processing affected both the thermal characteristics and the profile of phospholipids, since the content of phosphatidylcholine increased after the homogenization of pasteurized milk. The finding of this study could provide a valuable knowledge to dairy industry and the related applications since it highlights the variations in milk fat crystallization and melting behaviors, and the profile of phospholipids throughout a series of technological treatments.

Curcumin liposomes prepared with milk fat globule membrane phospholipids and soybean lecithin

Using thin film ultrasonic dispersion method, the curcumin liposomes were prepared with milk fat globule membrane (MFGM) phospholipids and soybean lecithins, respectively, to compare the characteristics and stability of the 2 curcumin liposomes. The processing parameters of curcumin liposomes were investigated to evaluate their effects on the encapsulation efficiency. Curcumin liposomes were characterized in terms of size distribution, ζ-potential, and in vitro release behavior, and then their storage stability under various conditions was evaluated. The curcumin liposomes prepared with MFGM phospholipids had an encapsulation efficiency of about 74%, an average particle size of 212.3nm, and a ζ-potential of −48.60mV. The MFGM liposomes showed higher encapsulation efficiency, smaller particle size, higher absolute value of ζ-potential, and slower in vitro release than soybean liposomes. The retention rate of liposomal curcumin was significantly higher than that of free curcumin. The stability of the 2 liposomes under different pH was almost the same, but MFGM liposomes displayed a slightly higher stability than soybean liposomes under the conditions of Fe3+, light, temperature, oxygen, and relative humidity. In conclusion, MFGM phospholipids have potential advantages in the manufacture of curcumin liposomes used in food systems.

Storage Stability and Physical Characteristics of Tea-Polyphenol-Bearing Nanoliposomes Prepared with Milk Fat Globule Membrane Phospholipids

The objective of this work was to better understand the functional properties of milk phospholipids when used as ingredients to prepare liposomes. Liposomal dispersions (10%) were prepared using high-pressure homogenization, and their physical properties as well as their ability to encapsulate tea polyphenols were investigated. The extent of encapsulation, measured by HPLC, increased with tea polyphenol concentration up to about 4 mg·mL(-1). At polyphenol concentrations ≥ 6 mg·mL(-1), the liposome dispersions were no longer stable. The influence of pH (3-7), storage temperature (room temperature or refrigeration), and addition of sugars (0-15%) were studied for liposomes containing 4 mg·mL(-1) polyphenols. The liposomal dispersions were also stable in the presence of peptides. The storage stability of the systems prepared with milk phospholipids was compared to that of liposomes made with soy phospholipids. Soy liposomes were smaller in size than milk phospholipid liposomes, the encapsulation efficiency was higher, and the extent of release of tea polyphenols during storage was lower for milk phospholipid liposomes compared to soy liposomes. The results suggest that milk phospholipids could be employed to prepare tea-polyphenol-bearing liposomes and that the tea catechins may be incorporated in the milk phospholipid bilayer more efficiently than in the case of a soy phospholipid bilayer.

Use of ultrafiltration and supercritical fluid extraction to obtain a whey buttermilk powder enriched in milk fat globule membrane phospholipids

Whey buttermilk, a by-product from whey cream processing to butter, is rich in milk fat globule membrane (MFGM) constituents, which have technological and potential health properties. The objective of this work was to produce a dairy ingredient enriched in MFGM material, especially phospholipids, from whey buttermilk. Whey buttermilk was concentrated by ultrafiltration (10×) and subsequently diafiltered (5×) (10 kDa molecular mass cutoff membrane) at 25 °C and the final retentate was spray-dried. The whey buttermilk powder was submitted to supercritical extraction (350 bar, 50 °C) using carbon dioxide. The membrane filtration removed most of the lactose and ash from the whey buttermilk, and the supercritical extraction extracted exclusively non-polar lipids. The final powder contained 73% protein and 21% lipids, of which 61% were phospholipids. This ingredient, a phospholipids-rich dairy powder, could be used as an emulsifier in different food systems.

Preparation of Liposomes from Milk Fat Globule Membrane Phospholipids Using a Microfluidizer

The isolation of milk fat globule membrane (MFGM) material from buttermilk on a commercial scale has provided a new ingredient rich in phospholipids and sphingolipids. An MFGM-derived phospholipid fraction was used to produce liposomes via a high-pressure homogenizer (Microfluidizer). This technique does not require the use of solvents or detergents, and is suitable for use in the food industry. The liposome dispersion had an average hydrodynamic diameter of 95nm, with a broad particle-size distribution. Increasing the number of passes through the Microfluidizer, increasing the pressure, or reducing the phospholipid concentration all resulted in a smaller average liposome diameter. Changing these variables did not have a significant effect on the polydispersity of the dispersion. Electron microscopy showed that the dispersions formed had a range of structures, including unilamellar, multilamellar, and multivesicular liposomes. The composition of the MFGM phospholipid material is different from that of the phospholipids usually used for liposome production in the pharmaceutical and cosmetic industries. The MFGM-derived fraction comprises approximately 25% sphingomyelin, and the fatty acids are primarily saturated and monounsaturated. These differences are likely to affect the properties of the liposomes produced from the phospholipid material, and it may be possible to exploit the unique composition of the MFGM phospholipid fraction in the delivery of bioactive ingredients in functional foods.

A carbohydrate-rich diet not only leads to incorporation of medium-chain fatty acids (6:0-14:0) in milk triglycerides but also in each milk-phospholipid subclass

We isolated phospholipid (PL) subclasses from milk of women in Dominica and Belize. Fatty acid (FA) compositions of PLs and total lipids were determined. In the total-lipid fraction Dominican milk showed higher relative amounts of medium-chain saturated fatty acids (MC-SAFAs; 6:0-14:0) and 22:6n-3 and lower amounts of long-chain saturated fatty acids (LC-SAFAs) and monounsaturated fatty acids (MUFAs). There was a positive relationship between the MC-SAFA content in total lipids and total PLs. Incorporation of MC-SAFAs in PLs occurred at the expense of LC-SAFAs, MUFAs, polyunsaturated fatty acids (PUFAs), and long-chain PUFAs with greater than or equal to 20 carbon atoms (LC-PUFAs greater than or equal to C20). Previous studies from Western countries revealed low amounts of MCSAFAs and high amounts of PUFAs and LC-PUFAs greater than or equal to C20 in milk PLs. Our data show that carbohydrate-rich diets give rise to incorporation of MC-SAFAs in PLs at the expense of PUFAs and LC-PUFAs greater than or equal to C20. The data are discussed in relation to the presumed origin of fat-globule membrane phospholipids.

Membranes of Mammary Gland. VII. Stability of Milk Fat Globule Membrane in Secreted Milk

Milk samples obtained from cows 1h after normal milking were separated into milk fat globule and serum fractionsat intervals during 96h of quiescent incubation. Fat globule membrane phospholipid decreased only slightly and structural enzymes 5′-nucleotidase and adenosine triphosphatase did not decrease during the 96h after collection of milk. These results together with previous observations argue against recent suggestions that the membrane surrounding milk fat globules is lost by vesiculation and shedding.

The lipid composition of microsomal preparations from lactating bovine mammary tissue.

AbstractThe microsomes isolated from lactating bovine mammary tissue contained 4.3 mg lipid per milligram nitrogen. Phospholipids comprised 83% of the lipids. The neutral lipids were composed of triglycerides (20–30%), diglycerides (5–10%), free fatty acids (15–30%, cholesterol (35–40% and cholesterol esters (10–12%, respectively. Phosphatidylcholine was the predominant phospholipid component (&gt;50%), and the remainder consisted of phosphatidylethanolamine (21–13%), phosphatidylserine (4–6%), phosphatidylinositol (8%), sphingomyelin (9%) and lysophosphatidylcholine (2%) respectively. The composition of the microsomal phospholipids was similar to that of isolated mammary cells and tissue homogenates but quite different from milk and fat globule membrane phospholipids. The triglycerides contained short chain fatty acids but their relative concentrations were lower than in milk triglycerides. The various lipid fractions had a variable proportion of saturated fatty acids, i.e., triglycerides (47.7%), diglycerides (86.7%), free fatty acids (70.6%), phosphatidylcholine (50.6%), phosphatidylethanolamine (50.8%), phosphatidylserine (35.3%), phosphatidylinositol (40.5%) and sphingomyelin (82.3%), respectively. The molecular distribution of fatty acids in the microsomal triglycerides and phosphatidylcholine was similar to that occurring in milk, i.e., the short chain and unsaturated fatty acids were concentrated in the primary positions (sn1 andsn3) of the triglycerides, and the unsaturated acids were preferentially located in positionsn2 of the phosphatidylcholine. The compositional data indicate that mammary microsomes are not the direct source of the phospholipids of the milk fat globule.

Membranes of Mammary Gland. III. Lipid Composition of Golgi Apparatus from Rat Mammary Gland

Purified Golgi apparatus fractions were obtained from mammary glands of lactating rats and were characterized morphologically and enzymologically. The lipid composition of the isolated fraction was determined and compared to rough endoplasmic reticulum and milk fat globule membranes. On a protein basis, Golgi apparatus and endoplasmic reticulum contained approximately the same amount of phospholipid. The Golgi apparatus fraction was rich in neutral lipid, most of which was due to triglyeeride-rich lipid droplets which adhered to the membranes. Golgi apparatus were intermediate between endoplasmic reticulum and milk fat globule membrane with respect to amounts of sphingomyelin, phosphatidyl choline, phosphatidyl inositol, and phosphatidyl ethanolamine. Golgi apparatus was also intermediate between the other two fractions with respect to membrane-bound sialic acid. The same fatty acids were found in both Golgi apparatus and milk fat globule membrane phospholipid classes. Results are compatible with the concept of Golgi apparatus-mediated cytomembrane differentiation.