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D E Bauman - One of the best experts on this subject based on the ideXlab platform.
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nutrigenomics rumen derived bioactive Fatty acids and the regulation of Milk Fat synthesis
Annual Review of Nutrition, 2011Co-Authors: D E Bauman, Kevin John Harvatine, A L LockAbstract:Mammary synthesis of Milk Fat continues to be an active research area, with significant advances in the regulation of lipid synthesis by bioactive Fatty acids (FAs). The biohydrogenation theory established that diet-induced Milk Fat depression (MFD) in the dairy cow is caused by an inhibition of mammary synthesis of Milk Fat by specific FAs produced during ruminal biohydrogenation. The first such FA shown to affect Milk Fat synthesis was trans-10, cis-12 conjugated linoleic acid, and its effects have been well characterized, including dose-response relationships. During MFD, lipogenic capacity and transcription of key mammary lipogenic genes are coordinately down-regulated. Results provide strong evidence for sterol response element-binding protein-1 (SREBP1) and Spot 14 as biohydrogenation intermediate responsive lipogenic signaling pathway for ruminants and rodents. The study of MFD and its regulation by specific rumen-derived bioactive FAs represents a successful example of nutrigenomics in present-day...
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nutrigenomics rumen derived bioactive Fatty acids and the regulation of Milk Fat synthesis
Annual Review of Nutrition, 2011Co-Authors: D E Bauman, Kevin John Harvatine, A L LockAbstract:Mammary synthesis of Milk Fat continues to be an active research area, with significant advances in the regulation of lipid synthesis by bioactive Fatty acids (FAs). The biohydrogenation theory established that diet-induced Milk Fat depression (MFD) in the dairy cow is caused by an inhibition of mammary synthesis of Milk Fat by specific FAs produced during ruminal biohydrogenation. The first such FA shown to affect Milk Fat synthesis was trans-10, cis-12 conjugated linoleic acid, and its effects have been well characterized, including dose-response relationships. During MFD, lipogenic capacity and transcription of key mammary lipogenic genes are coordinately down-regulated. Results provide strong evidence for sterol response element-binding protein-1 (SREBP1) and Spot 14 as biohydrogenation intermediate responsive lipogenic signaling pathway for ruminants and rodents. The study of MFD and its regulation by specific rumen-derived bioactive FAs represents a successful example of nutrigenomics in present-day animal nutrition research and offers several potential applications in animal agriculture.
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recent advances in the regulation of Milk Fat synthesis
Animal, 2009Co-Authors: Kevin John Harvatine, Yves R Boisclair, D E BaumanAbstract:: In addition to its economic value, Milk Fat is responsible for many of Milk's characteristics and can be markedly affected by diet. Diet-induced Milk Fat depression (MFD) was first described over a century ago and remains a common problem observed under both intensive and extensive management. The biohydrogenation theory established that MFD is caused by an inhibition of mammary synthesis of Milk Fat by specific Fatty acids (FA) produced as intermediates in ruminal biohydrogenation. During MFD, lipogenic capacity and transcription of key lipid synthesis genes in the mammary gland are down-regulated in a coordinated manner. Our investigations have established that expressions of sterol response element-binding protein 1 (SREBP1) and SREBP-activation proteins are down-regulated during MFD. Importantly, key lipogenic enzymes are transcriptionally regulated via SREBP1. Collectively, these results provide strong evidence for SREBP1 as a central signaling pathway in the regulation of mammary FA synthesis. Spot 14 is also down-regulated during MFD, consistent with a lipogenic role for this novel nuclear protein. In addition, SREBP1c and Spot 14 knock-out mice exhibit reduced Milk Fat similar to the magnitude and pattern of MFD in the cow. Application of molecular biology approaches has provided the latest chapter in the regulation of Milk Fat synthesis and is reviewed along with a brief background in nutritional regulation of Milk Fat synthesis in ruminants.
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trans 9 cis 11 conjugated linoleic acid reduces Milk Fat synthesis in lactating dairy cows
Journal of Dairy Science, 2007Co-Authors: James W Perfield, J. Mikko Griinari, Asgeir Saebo, Pierluigi Delmonte, Adam L. Lock, D.a. Dwyer, D E BaumanAbstract:Abstract Under certain dietary situations, rumen biohydrogenation results in the production of unique Fatty acids that inhibit Milk Fat synthesis. The first of these to be identified was trans -10, cis -12 conjugated linoleic acid (CLA), but others are postulated to contribute to diet-induced Milk Fat depression (MFD). Our objective was to examine the potential role of trans -9, cis -11 CLA in the regulation of Milk Fat. In a preliminary study, we used gas-liquid and high-performance liquid chromatography techniques to examine Milk Fat samples from a diet-induced MFD study and found that an increase in trans -9, cis -11 CLA corresponded to the decrease in Milk Fat yield. We investigated this further using a CLA enrichment of 9, 11 isomers to examine the biological effect of trans -9, cis -11 CLA on Milk Fat synthesis. Four rumen-fistulated Holstein cows were randomly assigned in a 4×4 Latin square experiment involving 5-d treatment periods and abomasal infusion of 1) ethanol (control), 2) a 9, 11 CLA mix (containing 32% trans -9, cis -11, 29% cis -9, trans -11, and 17% trans -9, trans -11), 3) a trans -9, trans -11 CLA supplement, and 4) a trans -10, cis -12 CLA supplement (positive control). The trans -9, trans -11 CLA and trans -10, cis -12 CLA supplements were of high purity (>90%), and all supplements were infused at a rate to provide 5 g/d of the CLA isomer of interest. Milk yield and dry matter intake did not differ among treatments. Compared with the control treatment, Milk Fat yield was reduced by 15% for the 9, 11 CLA mixture and by 27% for the trans -10, cis -12 CLA treatment. We also found that trans -9, trans -11 CLA had no effect on Milk Fat yield, and previous research has shown that Milk Fat yield is unaltered when cows are infused with cis -9, trans -11 CLA. When all treatments were considered, results suggested that trans -9, cis -11 was the CLA isomer in the 9, 11 CLA mix responsible for the reduction in Milk Fat synthesis, although the magnitude was less than that observed for trans -10, cis -12 CLA. Interestingly, trans -9, trans -11 CLA altered the Milk Fat desaturase index, further demonstrating that alterations in desaturase can occur independently of effects on Milk Fat synthesis. Overall, our investigations identified that an increase in Milk Fat content of trans -9, cis -11 CLA was associated with diet-induced MFD and provided evidence of a role for this isomer in MFD based on the 15% reduction in Milk Fat yield with abomasal infusion of a CLA enrichment that supplied 5 g/d of trans -9, cis -11 CLA.
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trans 10 octadecenoic acid does not reduce Milk Fat synthesis in dairy cows
Journal of Nutrition, 2007Co-Authors: A L Lock, Kevin John Harvatine, D.a. Dwyer, Cynthia Tyburczy, Frederic Destaillats, Zephirin Mouloungui, Laure Candy, D E BaumanAbstract:Diet-induced Milk Fat depression (MFD) involves the interrelation between rumen fermentation and mammary synthesis of Milk Fat, and the reduction in Milk Fat coincides with a marked increase in the trans-10 18:1 content of Milk Fat. Our objective was to directly examine the effect of trans-10 18:1 on Milk Fat synthesis in dairy cows. Three mid-lactation cows were used in a 3 x 3 Latin square design; treatments were abomasal infusion of: 1) ethanol (control); 2) trans-10 18:1 (t10); and 3) trans-10, cis-12 conjugated linoleic acid (CLA; positive control). The t10 and CLA supplements (>90% purity) were infused for 4 d and provided 42.6 and 4.3 g/d of trans-10 18:1 and trans-10, cis-12 CLA, respectively. Milk yield, feed intake, Milk protein, and Milk lactose were unaffected by treatment. Compared with the control, the t10 treatment had no effect on Milk Fat synthesis, whereas the CLA treatment resulted in a 27 and 24% reduction in Milk Fat content and yield, respectively. The transfer efficiency of the abomasally infused trans-10 18:1 and trans-10, cis-12 CLA into Milk Fat was 15 +/- 1 and 23 +/- 5% (means +/- SD), respectively. Overall, trans-10 18:1 had no effect on Milk Fat synthesis when abomasally infused at approximately 43 g/d, although it was taken up by the mammary glands and incorporated into Milk Fat. Therefore, our results offer no support for the concept that changes in rumen production of trans-10 18:1 within the physiological range play a role in the regulation of Fatty acid synthesis during diet-induced MFD.
A L Lock - One of the best experts on this subject based on the ideXlab platform.
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nutrigenomics rumen derived bioactive Fatty acids and the regulation of Milk Fat synthesis
Annual Review of Nutrition, 2011Co-Authors: D E Bauman, Kevin John Harvatine, A L LockAbstract:Mammary synthesis of Milk Fat continues to be an active research area, with significant advances in the regulation of lipid synthesis by bioactive Fatty acids (FAs). The biohydrogenation theory established that diet-induced Milk Fat depression (MFD) in the dairy cow is caused by an inhibition of mammary synthesis of Milk Fat by specific FAs produced during ruminal biohydrogenation. The first such FA shown to affect Milk Fat synthesis was trans-10, cis-12 conjugated linoleic acid, and its effects have been well characterized, including dose-response relationships. During MFD, lipogenic capacity and transcription of key mammary lipogenic genes are coordinately down-regulated. Results provide strong evidence for sterol response element-binding protein-1 (SREBP1) and Spot 14 as biohydrogenation intermediate responsive lipogenic signaling pathway for ruminants and rodents. The study of MFD and its regulation by specific rumen-derived bioactive FAs represents a successful example of nutrigenomics in present-day...
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nutrigenomics rumen derived bioactive Fatty acids and the regulation of Milk Fat synthesis
Annual Review of Nutrition, 2011Co-Authors: D E Bauman, Kevin John Harvatine, A L LockAbstract:Mammary synthesis of Milk Fat continues to be an active research area, with significant advances in the regulation of lipid synthesis by bioactive Fatty acids (FAs). The biohydrogenation theory established that diet-induced Milk Fat depression (MFD) in the dairy cow is caused by an inhibition of mammary synthesis of Milk Fat by specific FAs produced during ruminal biohydrogenation. The first such FA shown to affect Milk Fat synthesis was trans-10, cis-12 conjugated linoleic acid, and its effects have been well characterized, including dose-response relationships. During MFD, lipogenic capacity and transcription of key mammary lipogenic genes are coordinately down-regulated. Results provide strong evidence for sterol response element-binding protein-1 (SREBP1) and Spot 14 as biohydrogenation intermediate responsive lipogenic signaling pathway for ruminants and rodents. The study of MFD and its regulation by specific rumen-derived bioactive FAs represents a successful example of nutrigenomics in present-day animal nutrition research and offers several potential applications in animal agriculture.
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trans 10 octadecenoic acid does not reduce Milk Fat synthesis in dairy cows
Journal of Nutrition, 2007Co-Authors: A L Lock, Kevin John Harvatine, D.a. Dwyer, Cynthia Tyburczy, Frederic Destaillats, Zephirin Mouloungui, Laure Candy, D E BaumanAbstract:Diet-induced Milk Fat depression (MFD) involves the interrelation between rumen fermentation and mammary synthesis of Milk Fat, and the reduction in Milk Fat coincides with a marked increase in the trans-10 18:1 content of Milk Fat. Our objective was to directly examine the effect of trans-10 18:1 on Milk Fat synthesis in dairy cows. Three mid-lactation cows were used in a 3 x 3 Latin square design; treatments were abomasal infusion of: 1) ethanol (control); 2) trans-10 18:1 (t10); and 3) trans-10, cis-12 conjugated linoleic acid (CLA; positive control). The t10 and CLA supplements (>90% purity) were infused for 4 d and provided 42.6 and 4.3 g/d of trans-10 18:1 and trans-10, cis-12 CLA, respectively. Milk yield, feed intake, Milk protein, and Milk lactose were unaffected by treatment. Compared with the control, the t10 treatment had no effect on Milk Fat synthesis, whereas the CLA treatment resulted in a 27 and 24% reduction in Milk Fat content and yield, respectively. The transfer efficiency of the abomasally infused trans-10 18:1 and trans-10, cis-12 CLA into Milk Fat was 15 +/- 1 and 23 +/- 5% (means +/- SD), respectively. Overall, trans-10 18:1 had no effect on Milk Fat synthesis when abomasally infused at approximately 43 g/d, although it was taken up by the mammary glands and incorporated into Milk Fat. Therefore, our results offer no support for the concept that changes in rumen production of trans-10 18:1 within the physiological range play a role in the regulation of Fatty acid synthesis during diet-induced MFD.
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a conjugated linoleic acid supplement containing trans 10 cis 12 reduces Milk Fat synthesis in lactating sheep
Journal of Dairy Science, 2006Co-Authors: A L Lock, D E Bauman, James W Perfield, B M Teles, L A SinclairAbstract:Abstract The efficacy of conjugated linoleic acid (CLA) supplements containing trans -10, cis -12 for reducing Milk Fat synthesis has been well documented in dairy cows, but studies with other ruminant species are less convincing, and there have been no investigations of this in sheep. Therefore, the current study was designed to determine whether trans -10, cis -12 CLA would inhibit Milk Fat synthesis in sheep. Twenty multiparous ewes in early lactation were paired and randomly allocated to 2 treatments: grass hay plus concentrate either unsupplemented (control) or supplemented with lipid-encapsulated CLA to provide 2.4 g/d of trans -10, cis -12 CLA. The CLA dose was based on published responses of dairy cows extrapolated to ewes on a metabolic body weight basis. The experimental design was a 2-period crossover with 10-d treatment periods separated by a 10-d interval. Compared with the control, CLA supplementation reduced Milk Fat content from 6.4 to 4.9% and reduced Fat yield from 95 to 80 g/d. The CLA treatment also increased Milk yield from 1,471 to 1,611 g/d and increased protein yield from 68 to 73 g/d. Milk protein content and DMI were unaffected by treatment. The reduction in Milk Fat yield was due to decreases in both de novo Fatty acid synthesis and uptake of preformed Fatty acids. Milk Fat content of trans -10, cis -12 CLA was trans -10, cis -12 CLA from the dietary supplement into Milk Fat was 3.8%. Results of the present study demonstrate that a CLA supplement containing trans -10, cis -12 CLA reduces Milk Fat synthesis in lactating sheep in a manner similar to dairy cows when fed at an equivalent dose (metabolic body weight basis). Furthermore, the nutrients spared by the reduction in Milk Fat coincided with an increase in Milk and Milk protein yield.
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modifying Milk Fat composition of dairy cows to enhance Fatty acids beneficial to human health
Lipids, 2004Co-Authors: A L Lock, D E BaumanAbstract:There is increased consumer awareness that foods contain microcomponents that may have beneficial effects on health maintenance and disease prevention. In Milk Fat these functional food components include EPA, DHA, and CLA. The opportunity to enhance the content of these FA in Milk has improved as a result of recent advances that have better defined the interrelationships between rumen fermentation, lipid metabolism, and Milk Fat synthesis. Dietary lipids undergo extensive hydrolysis and biohydrogenation in the rumen. Milk Fat is predominantly TG, and de novo FA synthesis and the uptake of circulating FA contribute nearly equal amounts (molar basis) to the FA in Milk Fat. Transfer of dietary EPA and DHA to Milk Fat is very low (<4%); this is, to a large extent, related to their extensive biohydrogenation in the rumen, and also partly due to the fact that they are not transported in the plasma lipid fractions that serve as major mammary sources of FA uptake (TG and nonesterified FA). Milk contains over 20 isomers of CLA but the predominant one is cis-9,trans-11 (75–90% of total CLA). Biomedical studies with animal models have shown that this isomer has anticarcinogenic and anti-atherogenic activities. cis-9,trans-11-CLA is produced as an intermediate in the rumen biohydrogenation of linoleic acid but not of linolenic acid. However, it is only a transient intermediate, and the major source of Milk Fat CLA is from endogenous synthesis. Vaccenic acid, produced as a rumen biohydrogenation intermediate from both linoleic acid and linolenic acid, is the substrate, and Δ9-desaturase in the mammary gland and other tissues catalyzes the reaction. Diet can markedly affect Milk Fat CLA content, and there are also substantial differences among individual cows. Thus, strategies to enhance Milk Fat CLA involve increasing rumen outflow of vaccenic acid and increasing Δ9-desaturase activity, and through these, several-fold increases in the content of CLA in Milk Fat can be routinely achieved. Overall, concentrations of CLA, and to a lesser extent EPA and DHA, can be significantly enhanced through the use of diet formulation and nutritional management of dairy cows.
Kevin John Harvatine - One of the best experts on this subject based on the ideXlab platform.
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meta analysis of the relationship between Milk trans 10 c18 1 Milk Fatty acids 16 c and Milk Fat production
Journal of Dairy Science, 2020Co-Authors: C Matamoros, R N Klopp, L E Moraes, Kevin John HarvatineAbstract:ABSTRACT The economic value of Milk Fat and its responsiveness to management strategies provides strong interest in maximizing Milk Fat production by minimizing occurrence of biohydrogenation-induced Milk Fat depression (BH-MFD) and maximizing de novo synthesized Fatty acids (FA). Tools that allow a timely diagnosis of BH-MFD would improve nutritional management. Specific Milk FA or FA categories correlate to Milk Fat concentration and are of interest for diagnosing the cause of changes in Milk Fat concentration. The objective of the current study was to characterize the relationship between Milk Fat concentration and trans-10 C18:1, a proxy for BH-MFD, and FA
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acetate dose dependently stimulates Milk Fat synthesis in lactating dairy cows
Journal of Nutrition, 2017Co-Authors: N Urrutia, Kevin John HarvatineAbstract:: Background: Acetate is a short-chain Fatty acid (FA) that is especially important to cows because it is the major substrate for de novo FA synthesis. However, the effect of acetate supply on mammary lipid synthesis is not clear.Objective: The objective of this experiment was to determine the effect of increasing acetate supply on Milk Fat synthesis in lactating dairy cows.Methods: Six multiparous lactating Holstein cows were randomly assigned to treatments in a replicated design to investigate the effect of acetate supply on Milk Fat synthesis. Treatments were 0 (control), 5, 10, and 15 mol acetate/d continuously infused into the rumen for 4 d. Rumen short-chain FAs, plasma hormones and metabolites, Milk Fat concentration, and Milk FA profile were analyzed on day 4 of each treatment. Polynomial contrasts were used to test the linear and quadratic effects of increasing acetate supply.Results: Acetate increased Milk Fat yield quadratically (P < 0.01) by 7%, 16%, and 14% and increased Milk Fat concentration linearly (P < 0.001) by 6%, 9%, and 11% for 5, 10, and 15 mol acetate/d, respectively, compared with the control treatment. Increased Milk Fat yield predominantly was due to a linear increase in 16-carbon FAs (P < 0.001) and a quadratic increase in de novo synthesized FAs (<16-carbon FAs; P < 0.01), indicating that there was stimulation of de novo synthesis pathways. Apparent transfer of acetate to Milk Fat was 33.4%, 36.2%, and 20.6% for 5, 10, and 15 mol/d, respectively. Acetate infusion linearly increased the relative concentration of rumen acetate (P < 0.001) before feeding, but not after feeding. Acetate linearly increased plasma s-hydroxybutyric acid by 29%, 50%, and 78%, respectively, after feeding compared with the control treatment (P < 0.01).Conclusions: Increasing acetate supply to lactating cows increases Milk Fat synthesis, suggesting that nutritional strategies that increase ruminal acetate absorption would be expected to increase Milk Fat by increasing de novo FA synthesis.
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nutrigenomics rumen derived bioactive Fatty acids and the regulation of Milk Fat synthesis
Annual Review of Nutrition, 2011Co-Authors: D E Bauman, Kevin John Harvatine, A L LockAbstract:Mammary synthesis of Milk Fat continues to be an active research area, with significant advances in the regulation of lipid synthesis by bioactive Fatty acids (FAs). The biohydrogenation theory established that diet-induced Milk Fat depression (MFD) in the dairy cow is caused by an inhibition of mammary synthesis of Milk Fat by specific FAs produced during ruminal biohydrogenation. The first such FA shown to affect Milk Fat synthesis was trans-10, cis-12 conjugated linoleic acid, and its effects have been well characterized, including dose-response relationships. During MFD, lipogenic capacity and transcription of key mammary lipogenic genes are coordinately down-regulated. Results provide strong evidence for sterol response element-binding protein-1 (SREBP1) and Spot 14 as biohydrogenation intermediate responsive lipogenic signaling pathway for ruminants and rodents. The study of MFD and its regulation by specific rumen-derived bioactive FAs represents a successful example of nutrigenomics in present-day...
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nutrigenomics rumen derived bioactive Fatty acids and the regulation of Milk Fat synthesis
Annual Review of Nutrition, 2011Co-Authors: D E Bauman, Kevin John Harvatine, A L LockAbstract:Mammary synthesis of Milk Fat continues to be an active research area, with significant advances in the regulation of lipid synthesis by bioactive Fatty acids (FAs). The biohydrogenation theory established that diet-induced Milk Fat depression (MFD) in the dairy cow is caused by an inhibition of mammary synthesis of Milk Fat by specific FAs produced during ruminal biohydrogenation. The first such FA shown to affect Milk Fat synthesis was trans-10, cis-12 conjugated linoleic acid, and its effects have been well characterized, including dose-response relationships. During MFD, lipogenic capacity and transcription of key mammary lipogenic genes are coordinately down-regulated. Results provide strong evidence for sterol response element-binding protein-1 (SREBP1) and Spot 14 as biohydrogenation intermediate responsive lipogenic signaling pathway for ruminants and rodents. The study of MFD and its regulation by specific rumen-derived bioactive FAs represents a successful example of nutrigenomics in present-day animal nutrition research and offers several potential applications in animal agriculture.
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recent advances in the regulation of Milk Fat synthesis
Animal, 2009Co-Authors: Kevin John Harvatine, Yves R Boisclair, D E BaumanAbstract:: In addition to its economic value, Milk Fat is responsible for many of Milk's characteristics and can be markedly affected by diet. Diet-induced Milk Fat depression (MFD) was first described over a century ago and remains a common problem observed under both intensive and extensive management. The biohydrogenation theory established that MFD is caused by an inhibition of mammary synthesis of Milk Fat by specific Fatty acids (FA) produced as intermediates in ruminal biohydrogenation. During MFD, lipogenic capacity and transcription of key lipid synthesis genes in the mammary gland are down-regulated in a coordinated manner. Our investigations have established that expressions of sterol response element-binding protein 1 (SREBP1) and SREBP-activation proteins are down-regulated during MFD. Importantly, key lipogenic enzymes are transcriptionally regulated via SREBP1. Collectively, these results provide strong evidence for SREBP1 as a central signaling pathway in the regulation of mammary FA synthesis. Spot 14 is also down-regulated during MFD, consistent with a lipogenic role for this novel nuclear protein. In addition, SREBP1c and Spot 14 knock-out mice exhibit reduced Milk Fat similar to the magnitude and pattern of MFD in the cow. Application of molecular biology approaches has provided the latest chapter in the regulation of Milk Fat synthesis and is reviewed along with a brief background in nutritional regulation of Milk Fat synthesis in ruminants.
Christelle Lopez - One of the best experts on this subject based on the ideXlab platform.
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tempering governs the Milk Fat crystallisation and viscoelastic behaviour of unprocessed and homogenised creams
Food Research International, 2021Co-Authors: Amy Logan, Christelle Lopez, Li Day, Sofia K Oiseth, Mary Ann AugustinAbstract:Abstract The crystallisation behaviour of Milk Fat plays an important role in the functionality and sensory properties of Fat-rich dairy products. In this study, we investigated the impact of tempering to 25 °C on the viscoelastic properties, particle size and thermal behaviour of 20% w/w unprocessed and homogenised creams prepared from bovine Milk. The crystallisation properties were examined by synchrotron X-ray diffraction (XRD) at small (SAXS) and wide angle (WAXS) and differential scanning calorimetry (DSC). Oscillation rheology was performed to characterise the cream’s viscoelastic properties. Homogenisation (35 MPa) reduced the average droplet size from 4.4 to 1.3 µm. After 24 h storage at 4 °C, Milk Fat structures showed triacylglycerol (TAG) 2L and 3L(001, 002, 003, 005) lamellar stacking orders associated predominantly with the α and βˊ polymorphic forms. Tempering to 25 °C induced the complete melting of the 3L crystals and led to an irreversible loss in the elastic modulus (Gˊ) and a reduction in the viscous modulus (Gˊˊ) once returned to refrigerated conditions, due to changes in the particle–particle interactions and structure of the reformed Milk Fat crystals. The results demonstrate that crystallisation behaviour of Milk Fat is influenced by droplet size and the rearrangement of triacylglycerol (TAG) upon tempering, and lead to changes in the viscoelastic behaviour of dairy products containing a high level of Milk Fat.
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Effect of the size and interface composition of Milk Fat globules on their in vitro digestion by the human pancreatic lipase: Native versus homogenized Milk Fat globules
Food Hydrocolloids, 2012Co-Authors: Amélie Berton, Stéphanie Rouvellac, Benoît Robert, Christelle Lopez, Florence Rousseau, Isabelle CrenonAbstract:Although the bioavailability of dietary lipids is of primary importance in human nutrition and health, the mechanisms involved in lipid digestion are not fully understood and are of growing interest. The objective of this study was to determine the effect of the size of Milk Fat globules and of the composition of their interface on the activity of the human pancreatic lipase (PL). Native Milk Fat globules of various sizes covered by their biological membrane (MFGM) and homogenized Fat globules of various sizes covered by Milk proteins were prepared from whole Milk and underwent lipolysis by the human PL with colipase and bile salts. A lag phase preceding the hydrolysis of Milk TAG occurred with all native Milk Fat globules samples but not with homogenized Milk samples. The kinetic parameters of human PL were determined by measuring the enzyme activity either after the lag phase for native Milk Fat globules samples or immediately after the addition of the enzyme for homogenized Milk samples. The catalytic efficiency of human PL is 4.6-fold higher on small (1.8 μm) than large (6.7 μm) native Milk Fat globules, related to a 3.6-fold larger available surface. Despite the 25-fold larger available surface, Milk TAG from homogenized Milk are only 2-fold better hydrolyzed compared to native Milk Fat globules, as a possible result of a less favourable interface covered by Milk proteins. The potential mechanisms involved in native vs. homogenized Milk Fat globules digestion by the human PL are discussed. Our study highlights the crucial role of the MFGM in the efficient digestion of Milk Fat globules and brings new insight for the design of dairy products and infant formulas.
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buffalo vs cow Milk Fat globules size distribution zeta potential compositions in total Fatty acids and in polar lipids from the Milk Fat globule membrane
Food Chemistry, 2010Co-Authors: Olivia Menard, Valerie Briardbion, Sarfraz Ahmad, Florence Rousseau, Frederic Gaucheron, Christelle LopezAbstract:Although buffalo Milk is the second most produced Milk in the world, and of primary nutritional importance in various parts of the world, few studies have focused on the physicochemical properties of buffalo Milk Fat globules. This study is a comparative analysis of buffalo and cow Milk Fat globules. The larger size of buffalo Fat globules, 5 vs. 3.5 lm, was related to the higher amount of Fat in the buffalo Milks: 73.4 ± 9.9 vs. 41.3 ± 3.7 g/kg for cow Milk. Buffalo Milks contained significantly lower amount of polar lipids expressed per gram of lipids (0.26% vs. 0.36%), but significantly higher amount of polar lipids per litre of Milk (+26%). Buffalo and cow Milk Fat globule membranes contain the same classes of polar lipids; phosphatidylethanolamine, sphingomyelin (SM) and phosphatidylcholine (PC) being the main constituents. A significant higher percentage of PC and lower percentage of SM were found for buffalo Milks. The Fatty acid analysis revealed that saturated Fatty acids, mainly palmitic acid, trans Fatty acids, linolenic acid (x3) and conjugated linolenic acid were higher in buffalo Milk than in cow Milk. Such results will contribute to the improvement of the quality of buffalo Milk-based dairy products.
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crystallization properties and polymorphism of triacylglycerols in goat s Milk Fat globules
Journal of Agricultural and Food Chemistry, 2008Co-Authors: Wafa Ben Amaradali, Christelle Lopez, Pierre Lesieur, Michel OllivonAbstract:The sensorial, functional, and nutritional properties of goat dairy products result from the specific Fatty acid composition of goat’s Milk Fat. However, information on the physical and thermal properties of goat’s Milk Fat is scarce. In this study, crystallization of triacylglycerols (TG) in goat’s Milk Fat globules was investigated using polarized light microscopy and the coupling of time-resolved synchrotron radiation X-ray diffraction (XRD) and high-sensitivity differential scanning calorimetry (DSC). The molecular organization of the solid Fat phase was characterized for cooling rates between 3 and 0.1 °C/min. Quenching of goat’s Milk Fat globules from 50 to −8 °C and 4 °C was also examined to identify the most unstable polymorphic forms of TG. Then, the melting behavior of Fat crystals was studied on subsequent heating at 1 °C/min. Triple chain length (3L: 68.6−70 A) and double chain length (2L: 37−45.4 A) structures were characterized and 5 polymorphic forms, α, sub-α, β′1, β′2, and β were identifi...
Mark R. Ellersieck - One of the best experts on this subject based on the ideXlab platform.
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effects of Milk Fat cocoa butter or selected Fat replacers on flavor volatiles of chocolate ice cream
Journal of Dairy Science, 2001Co-Authors: W M Welty, Ingolf U Grun, R. T. Marshall, Mark R. EllersieckAbstract:Selected volatile compounds of chocolate ice creams containing 0.6, 4.0, 6.0, or 9.0% Milk Fat or containing 2.5% Milk Fat, cocoa butter, or one of three Fat replacers (Simplesse, Dairy Lo, or Oatrim) were analyzed by gas chromatography and gas chromatography-mass spectrometry using headspace solid-phase microextraction. The headspace concentration of most of the selected volatile compounds increased with decreasing Milk Fat concentration. Fat replacers generally increased the concentration of volatiles found in the headspace compared with Milk Fat or cocoa butter. Few differences in flavor volatiles were found between the ice cream containing Milk Fat and the ice cream containing cocoa butter. Among the selected volatiles, the concentration of 2,5-dimethyl-3(2-methyl propyl) pyrazine was the most highly correlated (negatively) with the concentration of Milk Fat, and it best discriminated among ice creams containing Milk Fat, cocoa butter, or one of the Fat replacers.