Anhydrous Milk Fat Research Articles

Microstructure and Material Properties of Milk Fat Systems During Temperature Fluctuations

Microstructure and material properties of milk fat systems containing different amount of milk fat globules and different emulsion types were studied towards the effects of temperature fluctuations stress. The three systems were (i) an emulsion based on anhydrous milk fat (AMF) consisting of crystals dispersed in liquid oil, (ii) butter which is a water in oil emulsion consisting of a continuous crystal network with partially disrupted fat globules interrupted by intact fat globules and water droplets, and (iii) freeze-dried cream which is an oil in water emulsion consisting of concentrated milk fat globules. The microstructure of the systems was observed by confocal laser scanning microscopy and linked to their material properties by large and small deformation rheology techniques. Different rheological techniques were used to characterize the material descriptors. The crystallization behavior was studied by thermal analysis and pulsed nuclear magnetic resonance. The freeze-dried cream was characterized as the softest, more elastic, and less stiff when compared to butter and AMF. Temperature fluctuations led to drastic material consolidation in butter as a consequence of flocculation of fat globules and formation of a more dense crystal network with stronger bonds. Only after several temperature fluctuations, material consolidation was observed in AMF, whereas no significant changes in material properties were observed in the freeze-dried cream. The intact fat globules decrease the hardness and stiffness, whereas the amount and type of contact points between crystal clusters of the dispersed crystal phase contribute to increase hardness, stiffness, and brittleness of the systems.

Effect of Lactose Monolaurate and High Intensity Ultrasound on Crystallization Behavior of Anhydrous Milk Fat

AbstractCrystallization behavior of anhydrous milk fat (AMF) was studied with the addition of 0.025 and 0.05 % lactose monolaurate (LML). The crystallization behavior was studied at low (ΔT = 3 °C) and high supercooling (ΔT = 6 °C). Polarized light microscopy and laser turbidimetry indicated a delay in crystallization on addition of 0.025 % and 0.05 % LML or Tween 20 to AMF. High intensity ultrasound (HIU) was applied to AMF samples with 0.05 % LML and lower supercooling (Tc = 31 °C; ΔT = 3 °C). HIU application in AMF and AMF + 0.05 % LML induced crystallization (p < 0.05) changing the induction time (τ) at 31 °C from 34.20 ± 1.67 min (AMF) and 47.07 ± 1.27 min (AMF + 0.05 % LML) to 23.23 ± 3.26 min (AMF) and 25.00 ± 0.87 min (AMF + 0.05 % LML). Melting enthalpies (ΔH) of AMF were significantly higher (p < 0.05) than the ones observed for AMF + 0.05 % LML when crystallized without HIU, while enthalpy values increased significantly in AMF + 0.05 % LML samples when crystallized with HIU reaching similar values to the ones obtained for AMF without LML. The viscosity of AMF significantly decreased (p < 0.05) on addition of 0.05 % LML and significantly increased on HIU application.

Shear and Rapeseed Oil Addition Affect the Crystal Polymorphic Behavior of Milk Fat

AbstractThe effect of shear on the crystallization kinetics of anhydrous milk fat (AMF) and blends with 20 and 30 % w/w added rapeseed oil (RO) was studied. Pulse 1H NMR was used to follow the α to β′ polymorphic transition. The NMR method was confirmed and supported by SAXS/WAXS experiments. Samples were crystallized at 5 °C and shear of 0, 74 or 444 s−1 was applied during early crystallization, in the NMR tube. High shear rates decreased the amount of α polymorph formed and accelerated the polymorphic transition; however, shear did not affect the final solid fat content (SFC). The α to β′ transition occurred faster in the presence of RO allowing more room for the conformational changes to occur. Final SFC decreased with increasing RO content. Shear applied in 20 and 30 % blends caused the destruction of β′‐related 3L structure leaving only 2L packing. In AMF and statically crystallized samples, both 3L and 2L packing existed. Shear did not affect the amount of β crystals formed. The study shows that both shear and RO affect the polymorphic behavior of milk fat, and that 1H NMR is able to detect polymorphic transition in blends with up to 30 % w/w RO.

Dietary anhydrous milk fat naturally enriched with conjugated linoleic acid and vaccenic acid modify cardiovascular risk biomarkers in spontaneously hypertensive rats

Saturated and trans fatty acids have been associated with the risk to develop cardiovascular diseases. However, health-promoting effects are associated with consumption of anhydrous milk fat (AMF) and ruminant trans fatty acids, such as conjugated linoleic acid (CLA) and vaccenic acid (VA) contained in the lipid fraction of milk and dairy products. The purpose of this study was to evaluate the effect of AMF naturally enriched with CLA and VA in spontaneously hypertensive rats (SHR), using sterculic oil to inhibit the conversion of VA into CLA. The administration of AMF to SHR during 7 weeks exerted beneficial effects on cardiovascular risk biomarkers (reduction of insulin, blood lipids, increase of adiponectin). When sterculic oil was included, some parameters were further ameliorated (reduction of insulin, increase of adiponectin). Sterculic oil alone reduced body weight and adiposity, and improved blood pressure, adiponectin and triglyceride levels.

Improved Lactose Powder Properties by In-situ Coating with Additives during Spray Drying

 Abstract—The ability of different additives to enrich on the droplet surface during spray drying of aqueous lactose solutions was investigated. The goal of this study was to find an additive coating that increases spray-dryer yield, improves powder flow and prevents caking due to lactose crystallization during storage. The additives tested were Nacaseinate (NaCas), gelatin, lecithin, anhydrous milk fat (AMF) and hydroxylpropyl methylcellulose (HPMC). The aqueous lactose solutions had 10 weight% solids content with a lactose-to-additive dry weight ratio of 9:1. All additives enrich significantly on the droplet surface at the expense of lactose during spray drying. Every additive except AMF enhances the glass transition temperature at the particulate surface and therefore reduces particle stickiness, as demonstrated by improved powder flow and/or product yield compared with the pure lactose powder. Low product yield for HPMC-containing lactose powder can be explained by its low bulk density, which reduces the separation efficiency of the cyclone. Poor powder flow for lecithin-containing lactose powder can be explained by its agglomerated nature. AMF is not suitable as an additive due to a low product yield and poor powder flow, a result of stickiness due to the low melting point of fat. None of the additives improve the wetting time of lactose powder, since lactose is already highly hydrophilic, and most of the additives tend to make the particle surface more hydrophobic. NaCas and HPMC are the most promising additives with regards to improving powder flow. NaCas results in a higher product yield than HPMC, but HPMC is the only additive that provides a protective coating for lactose capable of preventing the formation of a hard brittle cake upon lactose crystallization during storage at ambient room conditions.

Dietary Fat Composition Influences Tissue Lipid Profile and Gene Expression in Fischer‐344 Rats

The AIN-76A diet causes fatty liver in rodents when fed for long periods of time. The aim of this study was to utilize fatty acid analysis and transcriptomics to investigate the effects of different fat sources in the AIN-76A diet on tissue lipid profiles and gene expression in male, weanling Fischer-344 rats. Animals were fed isocaloric diets that differed only in the fat source: (1) corn oil (CO) (2) anhydrous milk fat (AMF), and (3) AMF supplemented with 10% phospholipids from the milk fat globule membrane (AMF-MFGM). There were no differences in food intake, body weight, growth rate, or body fat composition among the groups, and the fatty acid compositions of red blood cells (RBC), plasma, muscle, and visceral adipose tissues reflected the dietary fat sources. Modifying the fat source resulted in 293 genes differentially regulated in skeletal muscle, 1,124 in adipose, and 831 in liver as determined by analysis of variance (ANOVA). Although tissue fatty acid profiles mostly reflected the diet, there were several quantitative differences in lipid classes in the liver and plasma. The AMF diet resulted in the highest level of hepatic triacylglycerols, but the lowest level in plasma. The CO diet resulted in significant accumulation of hepatic unesterified fatty acids and decreased DGAT expression and activity, a potential trigger for steatohepatitis. These results indicate that the fatty acid composition and presence of polar lipids in the AIN-76A diets have significant effects on lipid partitioning, gene expression, and potentially the development of liver pathology.

Shear-induced Crystal Structure Formation in Milk Fat and Blends with Rapeseed Oil

The effect of shear on the rheological properties of anhydrous milk fat (AMF) and blends added 10–30 w/w% rapeseed oil (RO) was studied. Shear was applied during early crystallization, and the complex modulus |G*| was measured during the final isothermal crystallization. The firmest and most rapidly formed network was achieved when an intermediate shear of 50 s−1 was applied, and at this shear rate, up to 20 % RO could be added without lowering the final |G*| compared to pure AMF. A similar effect was not obtained at lower or higher shear rates. Solid fat content was unaffected by shear, while fat crystal size decreased upon increasing shear rate. The study indicates that intermediate shear produces a continuous and strong crystal network, while high shear breaks down the microstructure to such an extent that it is difficult to rebuild during subsequent crystallization, thus resulting in lower |G*|.

Effect of pressure-assisted thermal sterilization on conjugated linoleic acid (CLA) content in CLA-enriched milk

Conjugated linoleic acid (CLA) has been recently studied for its health-promoting and disease-preventing properties. The objective of this study was to evaluate the effect of pressure (100–600 MPa), temperature (60–120 °C) and treatment time (0–14 min) on CLA content in milk and anhydrous milk fat (AMF) rich in CLA. In milk treated up to 14 min at 100 MPa, CLA was stable (> 80% of retention), regardless of the temperature. In contrast, only 3.4 ± 2% of CLA was retained at 600 MPa and 120 °C. For AMF, CLA retention was considerably higher (40.2 ± 2%) than that obtained for milk. The presence of free metal ions in milk might catalyze CLA degradation. When the antioxidant catechin (1 g/kg) was used, CLA retention increased significantly (> 90%) in milk and AMF, regardless of the experimental conditions. Previous research led by Dr. John Kennelly resulted in CLA-enriched milk by manipulating the diet of dairy cattle. CLA in milk suffers significant losses in terms of its biological activity during processing at high temperatures like UHT. High consumption of CLA products has been associated with many health benefits. This study provided new data on CLA retention with and without an antioxidant at pressure-assisted thermal sterilization (PATS) conditions and confirmed the role of catechin in reducing oxidative damage by PATS treatments. Milk rich in CLA can be treated with PATS to deliver shelf-stable milk while CLA activity is preserved.

Estimation of Protein in Anhydrous Milk Fat

A method for the estimation of protein in anhydrous milk fat is described. The protein concentration is estimated by quantifying the arginine and aspartic acid (ASX) released upon acid hydrolysis of the anhydrous milk fat. Arginine and aspartic acid are derivatized with the fluorescent tag 9-fluorenylmethoxycarbonyl (FMOC), the derivatives are quantified by reversed phase HPLC, and the protein concentration in the anhydrous milk fat is estimated as 8.77 × (Arg + ASX). Method suitability was defined by experimental assessments of FMOC-arginine and FMOC-aspartic acid linearity (R 2 averages > 0.999), protein estimate precision [day-to-day RSD values (n = 8 days) ranged from 7.3 to 14 % for protein concentrations of 9.42 to 40.0 mg/kg of anhydrous milk fat], protein estimate accuracy [spike recovery average = 95.6 % (9.3 %), n = 8, spiking level = 20 mg/kg and agreement of the experimental protein estimate for butter, 0.611 (0.044) g/100 g, n = 3 lots, with a published value 0.6/100 g], and analyte selectivity (baseline resolution of FMOC-arginine and FMOC-aspartic acid from the FMOC derivatives of other common amino acids). The method provides for a reliable estimation of the protein content of anhydrous milk fat, when present at concentrations >2 mg/kg.

Dietary conjugated linoleic acid reshapes high fat diet‐induced microbiota and reduces its immunogenicity

The composition of human gut microbiota has shifted over the last century, leading to increased prevalence of autoimmune diseases, such as inflammatory bowel diseases. Shifts in dietary intake to Westernized high fat high carbohydrate diet has influenced this phenomenon. Restoring gut microbiota to a less immunogenic state by altering diet to alleviate gut inflammation is a focus of our research. We hypothesized that supplementing conjugated linoleic acids (CLA), a group of fatty acids with anti‐inflammatory properties, in the presence of high fat diet would result in reshaping the gut microbiota to a less immunogenic state. Mice were fed 18% anhydrous milk fat (AMF) or 18% safflower oil diet with or without CLA for 3 weeks. Microbial 16s rRNA profiles of cecal contents were analyzed via Sanger‐based sequencing. Using wild type spleen‐derived dendritic cells, cecal lysate immunogenicity index was determined by comparing IL‐12p40/IL‐ 10 ratio after culture. Dietary CLA reshaped the enteric microbiota by increasing Firmicutes/Bacteroidetes ratio compared to AMF alone and resulted in decreased δ‐proteobacteria. Lastly, CLA supplementation significantly reduced immunogenicity of cecal lysate. These data suggest dietary CLA supplementation can restore the gut microbiome in the presence of high fat diet and could have positive clinical implications for IBD patients.Grant Funding Source : 5T32DK007074‐38

Physicochemical and structural properties of compound dairy fat blends

The physicochemical properties of fat model systems made of commercial samples of anhydrous milk fat (AMF) or a fraction blended with palm oil (PO) were studied. Physical properties such as solid fat content, melting curves by differential scanning calorimetry, textural properties, and polymorphism were investigated. The objective of the present work was to systematically map interactions (compatibility/incompatibility) that occur in such model of compound fat systems with respect to butyric-based shortening or butter-like spreads formulations.For that purpose, iso-solid diagrams have been constructed from p-NMR data. Molecular interactions have been highlighted for all the blends, especially at low temperatures. Compositions at which molecular interactions were detected depend on the TAGs composition of the fractions involved in the blends. For example, under dynamic conditions, a minimum was observed (eutectic interaction) for all the blends. This minimum was shifted to higher PO content for blends made of AMF fractions with lower iodine value (IV) and to lower PO content for AMF with higher IV. After static crystallization followed by a tempering at 15°C, interactions also existed for all the blends. It was shown that the deviations found in hardness after this tempering procedure can be explained by intersolubility, polymorphic and microstructure arguments. Practical applicationsResults reported here concern physical characteristics of several compound fat blends (butyric–vegetal). A comprehensive analysis of binary fat blends made of AMF, or its fractions, blended with a vegetal fat was conducted. This better understanding of crystallization phenomena occurring is required to further enhance the use of AMF in compound-margarines and shortenings. Indeed phase properties of fat blends have a significant influence on the sensorial characteristics of the final products (hardness, brittleness, grainy or smooth texture, …). This study is relevant for the dairy food industry as it may contribute to the development of new mixed-fat products, also sometimes called dairy blends.

The effect of cooling rate and rapeseed oil addition on the melting behaviour, texture and microstructure of anhydrous milk fat

Anhydrous milk fat and blends containing up to 40% (w/w) rapeseed oil (RO) were crystallized using a slow (0.05 °C min−1) or fast (5 °C min−1) cooling rate. Melting behaviour was examined using differential scanning calorimetry, texture was analysed by parallel plate compression tests, microstructure was studied by confocal laser scanning microscopy, and solid fat content was measured by pulse-NMR. Fast cooling of the blends decreased the peak melting temperature of both high and low melting fractions of milk fat as the content of RO increased, while increasing RO combined with slow cooling did not affect melting behaviour. Solvent effects dominating in fast cooled samples are suggested to be responsible for the change in melting behaviour. The texture of fast cooled samples correlated with solid fat content. In slow cooled samples addition of RO decreased the hardness, which was ascribed to an increase in crystal cluster size.

Adequacy of creamy requeijão cheese to the standards of identity and quality and the labeling standards

The creamy Requeijao cheese is a type of creamy Requeijao cheese, obtained from the fusion of a washed drained curd obtained through acid and /or enzymatic coagulation of milk with the addition of cheese cream and/or butter and/or anhydrous milk fat or butter oil. This study evaluates the adequacy of creamy Requeijao cheeses produced by micro and small companies in the southern region of Minas Gerais, according to the standards of food legislation, to identify possible problems. The chemical composition on the three batches was analyzed, and the results of fat in dry matter and moisture, compared to the requirements of the Technical Regulation for Identification and Quality of Requeijao cheese. The adequacy of the labeling of products according to the provisions in the current Brazilian Legislation on food labeling was also evaluated. It was observed that all creamy Requeijao cheeses analyzed showed irregularities regarding the Technical Regulation for Identification and Quality of Requeijao cheese and the standards for food labeling. Thus it is evident the need for actions to improve the quality of the creamy Requeijao cheeses analyzed and to be in accordance to the legislation.

Characterization of the Stearin Obtained by Thermal Fractionation of Anhydrous Milk Fat

Thermal fractionation of anhydrous milk fat with high initial content of low molecular weight TAGs was performed based on a 2 2 factorial experimental design with three central and two axial points. The independent variables were the crystallization temperature and the cooling rate. A 2.0 L agitated glass reactor was used and the rotation was kept at 20 rpm. The filtration was performed under vacuum (500 mmHg), using a 14 μm average pore diameter filter paper. Curves of isothermal crystallization of the stearin fraction showed that increasing the crystallization temperature, increases the induction period and decreases the maximum solid content of stearin. An increase of the crystallization temperature resulted in an increase in solid fat content. All runs achieved an efficient fractionation using a single separation step and stearin with defined characteristics can be obtained adapting the process conditions.

Enzymatic hydrolysis of conjugated linoleic acid-enriched anhydrous milk fat in supercritical carbon dioxide

Consumption of conjugated linoleic acid (CLA) has been associated with numerous health benefits. CLA in its free form can be obtained by enzymatic hydrolysis of milk fat. In this study, enzymatic hydrolysis of CLA-enriched anhydrous milk fat (AMF) using supercritical CO2 and Lipozyme TL IM were carried out to maximize the production of free fatty acids (FFAs). The effects of pressure (20–30MPa), fat:water ratio (1:5–1:30mol/mol) and their interaction in the FFA production were studied using response surface methodology. After performing the optimization, reactions at two different temperatures (45 and 65°C) and then with three different enzymes (Lipozyme RM IM, Novozyme 435, and immobilized enzyme from Candida rugosa) were carried out to assess the optimum FFA production. CLA content in its free form and major lipid classes (FFA, monoglycerides (MG), diglycerides (DG), and triglycerides (TG)) in the reaction products were quantified by gas chromatography. An increase in FFA and intermediate reaction products (MG and DG), together with a decrease in TG compared to the starting material was observed at all experimental conditions studied. The maximum level of FFA (86.79%, w/w) was achieved using Lipozyme TL IM at 23MPa, 1:5 fat:water ratio (mol/mol) and 55°C. The maximum CLA content in FFA form (6.81mg/gfat) was obtained using Lipozyme TL IM at 30MPa, 1:30 fat:water ratio (mol/mol) and 55°C that corresponds to 98% conversion of CLA in TG form to FFA form.

A comparative study of the composition of triacylglycerol molecular species in equine and human milks

The composition of triacylglycerols (TAGs) is a very useful parameter to understand several properties of creams and anhydrous milk fat products such as nutritional value, technological applications, and textural properties. In this paper, the molecular species of TAGs of equine milk were identified using a combination of non-aqueous reversed phase high-performance liquid chromatography, electrospray ionization mass spectrometry and high temperature gas chromatography and were then compared to the TAGs composition of human milk. The data showed that equine milk contained a complex mixture of different TAGs molecular species resulting from the widest range of its fatty acids as compared to human milk. In particular, the largest differences in TAGs composition between equine and human milk concerned TAGs containing medium-chain fatty acids; for C8, C10, and C12. In terms of carbon number (CN), TAGs with CN36–CN46 were the most abundant in equine milk with a maximum concentration at CN44 (15.3%), while TAGs with CN44–CN52 were the predominant in human milk with a maximum of CN52 (30%). For both milks studied, the experimentally determined distributions of TAGs molecular species deviated from those predicted by the random hypothesis. TAGs with CN44 corresponding to a fatty acids carbon number distribution of C8/C18/C18, C12/C14/C18, and C10/C16/C18 were apparently preferentially synthesized in equine milk. Whereas, in human milk, mixed TAGs with CN52 containing C16/C18/C18 fatty acids were much higher than would be expected from the random calculation.

Dairy milk fat augments paclitaxel therapy to suppress tumour metastasis in mice, and protects against the side-effects of chemotherapy

Milk fat is a natural product containing essential nutrients as well as fatty acids and other food factors with reported anti-cancer potential. Here bovine milk fat was tested for its ability to inhibit the growth of breast and colon cancers and their metastasis to the lung and liver; either alone or in combination with the chemotherapeutic agent paclitaxel. A diet containing 5% typical anhydrous milk fat (representing ~70% of the total dietary fat component) fed to Balb/c mice delayed the appearance of subcutaneous 4T1 breast and CT26 colon cancer tumours and inhibited their metastasis to the lung and liver, when compared to the control diet containing soybean oil as the only fat component. It augmented the inhibitory effects of paclitaxel on tumour growth and metastasis, and reduced the microvessel density of tumours. It displayed no apparent organ toxicity, but instead was beneficial for well-being of tumour-bearing mice by maintaining gastrocnemius muscle and epididymal adipose tissue that were otherwise depleted by cachexia. The milk fat diet ameliorated gut damage caused by paclitaxel in non-tumour-bearing mice, as evidenced by retention of jejunal morphology, villi length and intestinal γ-glutamyl transpeptidase activity, and inhibition of crypt apoptosis. It prevented loss of red and white blood cells due to both cancer-mediated immunosuppression and the cytotoxic effects of chemotherapy. The present study warrants the use of milk fat as an adjuvant to inhibit tumour metastasis during cancer chemotherapy, and to spare patients from the debilitating side-effects of cytotoxic drugs.

Kinetics of non-isothermal oxidation of anhydrous milk fat rich in conjugated linoleic acid using differential scanning calorimetry

Abstract Anhydrous milk fat (AMF) with low, medium, and high content of conjugated linoleic acid (L-, M-, and H-CLA) was oxidized using differential scanning calorimetry (DSC) at five different heating rates (3, 6, 9, 12, and 15 °C min−1) in a temperature range of 100–350 °C. For the first time, kinetic oxidation parameters of AMF rich in CLA are reported. DSC spectra were analyzed to locate the start temperature (Ts), onset temperature (Ton), and maximum heat flow temperature (Tp). These reference points were further used to calculate the effective activation energy (E) and pre-exponential factor (z) using the Ozawa-Flynn-Wall method. The Ts shifts to lower values as the CLA content increases, while the Ton and Tp were less affected by the CLA content. The calculated kinetic parameters not only depend on the ratio between unsaturated to saturated fatty acids but also on the selected reference points. For the L-CLA sample, the E values calculated from Ts, Ton, and Tp were 146.51, 114.11, and 121.31 kJ mol...

Effects of antisense-mediated inhibition of 11β-hydroxysteroid dehydrogenase type 1 on hepatic lipid metabolism

11β-hydroxysteroid dehydrogenase 1 (11β-HSD1) converts inactive 11-keto derivatives to active glucocorticoids within tissues and may play a role in the metabolic syndrome (MS). We used an antisense oligonucleotide (ASO) to knock down 11β-HSD1 in livers of C57BL/6J mice consuming a Western-type diet (WTD). 11β-HSD1 ASO-treated mice consumed less food, so we compared them to ad libitum-fed mice and to food-matched mice receiving control ASO. Knockdown of 11β-HSD1 directly protected mice from WTD-induced steatosis and dyslipidemia by reducing synthesis and secretion of triglyceride (TG) and increasing hepatic fatty acid oxidation. These changes in hepatic and plasma lipids were not associated with reductions in genes involved in de novo lipogenesis. However, protein levels of both sterol regulatory element-binding protein (SREBP) 1 and fatty acid synthase were significantly reduced in mice treated with 11β-HSD1 ASO. There was no change in hepatic secretion of apolipoprotein (apo)B, indicating assembly and secretion of smaller apoB-containing lipoproteins by the liver in the 11β-HSD1-treated mice. Our results indicate that inhibition of 11β-HSD1 by ASO treatment of WTD-fed mice resulted in improved plasma and hepatic lipid levels, reduced lipogenesis by posttranslational regulation, and secretion of similar numbers of apoB-containing lipoproteins containing less TG per particle.

Membrane-rich milk fat diet provides protection against gastrointestinal leakiness in mice treated with lipopolysaccharide

Milk fat globule membrane is a protein-lipid complex that may strengthen the gut barrier. The main objective of this study was to assess the ability of a membrane-rich milk fat diet to promote the integrity of the gut barrier and to decrease systemic inflammation in lipopolysaccharide (LPS)-challenged mice. Animals were randomly assigned to one of 2 American Institute of Nutrition (AIN)-76A formulations differing only in fat source: control diet (corn oil) and milk fat diet (anhydrous milk fat with 10% milk fat globule membrane). Each diet contained 12% calories from fat. Mice were fed diets for 5 wk, then injected with vehicle or LPS (10mg/kg of BW) and gavaged with dextran-fluorescein to assess gut barrier integrity. Serum was assayed for fluorescence 24h after gavage, and 16 serum cytokines were measured to assess the inflammatory response. Gut permeability was 1.8-fold higher in LPS-challenged mice fed the control diet compared with the milk fat diet. Furthermore, mice fed the milk fat diet and injected with LPS had lower serum levels of IL-6, IL-10, IL-17, monocyte chemotactic protein (MCP)-1, interferon (IFN)-γ, tumor necrosis factor (TNF)-α, and IL-3 compared with LPS-injected mice fed the control diet. The results indicate that the membrane-rich milk fat diet decreases the inflammatory response to a systemic LPS challenge compared with corn oil, and the effect coincides with decreased gut permeability.