551
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Byrdwell WC, Perry RH. Liquid chromatography with dual parallel mass spectrometry and 31P nuclear magnetic resonance spectroscopy for analysis of sphingomyelin and dihydrosphingomyelin. J Chromatogr A 2007; 1146:164-85. [PMID: 17303148 DOI: 10.1016/j.chroma.2007.01.108] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2006] [Revised: 01/25/2007] [Accepted: 01/29/2007] [Indexed: 10/23/2022]
Abstract
Liquid chromatography coupled to atmospheric pressure chemical ionization (APCI) and electrospray ionization (ESI) mass spectrometry (MS), in parallel, was used for simultaneous detection of bovine milk sphingolipids (BMS). APCI-MS mass spectra exhibited mostly ceramide-like fragment ions, [Cer-H(2)O+H](+) and [Cer-2H(2)O+H](+), which were used to identify individual molecular species of BMS according to fatty acyl chain length:degree of unsaturation and long-chain base (LCB). ESI-MS was used to confirm the molecular weights of BMS species. Both sphingomyelin (SM) and dihydrosphingomyelin (DSM) molecular species were identified, with DSM species constituting 20% of BMS. Approximately 56 to 58% of DSM species contained a d16:0 LCB, while 34 to 37% contained a d18:0 LCB. Approximately 26 to 30% of SM species contained a d16:1 LCB, while 57 to 60% contained a d18:1 LCB. BMS species contained both odd and even carbon chain lengths. The most abundant DSM species contained a d16:0 LCB with a 22:0, 23:0 or 24:0 fatty acyl chain, while the most abundant SM species contained a d18:1 LCB with a 16:0 or 23:0 fatty acyl chain. (31)P NMR spectroscopy was used to conclusively confirm that DSM is a dietary component in BMS.
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Affiliation(s)
- Wm Craig Byrdwell
- Food Composition Laboratory, U.S. Department of Agriculture Agricultural Research Service-BHNRC, Beltsville, MD 20904, USA.
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552
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Michalski MC. On the supposed influence of milk homogenization on the risk of CVD, diabetes and allergy. Br J Nutr 2007; 97:598-610. [PMID: 17349070 DOI: 10.1017/s0007114507657900] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Commercial milk is homogenized for the purpose of physical stability, thereby reducing fat droplet size and including caseins and some whey proteins at the droplet interface. This seems to result in a better digestibility than untreated milk. Various casein peptides and milk fat globule membrane (MFGM) proteins are reported to present either harmful (e.g. atherogenic) or beneficial bioactivity (e.g. hypotensive, anticarcinogenic and others). Homogenization might enhance either of these effects, but this remains controversial. The effect of homogenization has not been studied regarding the link between early cow's milk consumption and occurrence of type I diabetes in children prone to the disease and no link appears in the general population. Homogenization does not influence milk allergy and intolerance in allergic children and lactose-intolerant or milk-hypersensitive adults. The impact of homogenization, as well as heating and other treatments such as cheesemaking processes, on the health properties of milk and dairy products remains to be fully elucidated.
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553
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554
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Changes in the pool of free fatty acids in ovine, bovine and caprine milk fats, effected by viable cells and cell-free extracts of Lactococcus lactis and Debaryomyces vanrijiae. Food Chem 2007. [DOI: 10.1016/j.foodchem.2006.10.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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555
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Golay PA, Dionisi F, Hug B, Giuffrida F, Destaillats F. Direct quantification of fatty acids in dairy powders with special emphasis on trans fatty acid content. Food Chem 2007. [DOI: 10.1016/j.foodchem.2006.03.011] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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556
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Goat's alpha-s1 casein genotype influences its milk fatty acid composition and delta-9 desaturation ratios. Anim Feed Sci Technol 2006. [DOI: 10.1016/j.anifeedsci.2006.05.025] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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557
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558
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559
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560
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Dewhurst R, Shingfield K, Lee M, Scollan N. Increasing the concentrations of beneficial polyunsaturated fatty acids in milk produced by dairy cows in high-forage systems. Anim Feed Sci Technol 2006. [DOI: 10.1016/j.anifeedsci.2006.04.016] [Citation(s) in RCA: 269] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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561
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562
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563
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Byrdwell WC, Perry RH. Liquid chromatography with dual parallel mass spectrometry and 31P nuclear magnetic resonance spectroscopy for analysis of sphingomyelin and dihydrosphingomyelin. J Chromatogr A 2006; 1133:149-71. [PMID: 16938303 DOI: 10.1016/j.chroma.2006.08.014] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2006] [Revised: 08/05/2006] [Accepted: 08/08/2006] [Indexed: 11/16/2022]
Abstract
Liquid chromatography coupled to atmospheric pressure chemical ionization (APCI) and electrospray ionization (ESI) mass spectrometry (MS), in parallel, was used for detection of bovine brain and chicken egg sphingolipids (SLs). APCI-MS mass spectra exhibited mostly ceramide-like fragment ions, [Cer-H(2)O+H](+) and [Cer-2H(2)O+H](+), whereas ESI-MS produced mostly intact protonated molecules, [M+H](+). APCI-MS/MS and MS(3) were used to differentiate between isobaric SLs. APCI-MS/MS mass spectra exhibited long-chain base related fragments, [LCB](+) and [LCB-H(2)O](+), that allowed the sphinganine backbone to be differentiated from the sphingenine backbone. Fragments formed from the fatty amide chain, [FA(long)](+) and [FA(short)](+), allowed an overall fatty acid composition to be determined. The presence of both dihydrosphingomyelin (DSM) and sphingomyelin (SM) sphingolipid classes was confirmed using (31)P NMR spectroscopy.
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564
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Skeaff CM, Gowans S. Home use of margarine is an important determinant of plasma trans fatty acid status: a biomarker study. Br J Nutr 2006; 96:377-83. [PMID: 16923234 DOI: 10.1079/bjn20061737] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The contribution of the home use of margarines, made with partially hydrogenated vegetables oils, to total trans fatty acid intake is difficult to determine using dietary assessment because food composition databases are incomplete for trans fatty acids; moreover, hidden fats in manufactured foods may be the predominant sources of trans fatty acids. The objective of our study was to determine, using plasma phospholipid trans fatty acid composition as a surrogate measure of exposure, whether the home use of margarine or butter is an important determinant of trans fatty acid status. We conducted a community-based (Dunedin, New Zealand), cross-sectional survey of people who consumed either margarine (n 65) or butter (n 64) but not both for home use. The levels of the 18:1 trans isomers commonly found in partially hydrogenated vegetable oils were all significantly higher in the plasma phospholipids of margarine compared with butter consumers, with the exception of 18:1n-7t, which did not differ. Among margarine consumers, the percentage of total fat from margarine was significantly correlated with levels of phospholipid 18:1n-6t, 18:1n-8t and 18:1n-12/9t isomers (r 0.57-0.63, P<0.001) but only weakly with 18:1n-7t (r 0.30, P=0.016). The intake of fat from fast foods, bakery products or meat and meat products was not associated with plasma phospholipid trans isomeric composition. The home use of margarine, made with partially hydrogenated vegetable oils, is an important determinant of trans fatty acid exposure in New Zealand.
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Affiliation(s)
- C Murray Skeaff
- Department of Human Nutrition, University of Otago, Dunedin, New Zealand.
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565
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Clément M, Tremblay J, Lange M, Thibodeau J, Belhumeur P. Whey-derived free fatty acids suppress the germination of Candida albicans in vitro. FEMS Yeast Res 2006; 7:276-85. [PMID: 17034417 DOI: 10.1111/j.1567-1364.2006.00166.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Bovine whey from the cheese-making industry contains several bioactive factors that promote health and prevent disease. Although many efforts have been made over the years to show that immunoglobulins, lactoperoxidase, lactoferrin, lysosyme and small peptides present in whey have antimicrobial activities against several pathogenic microorganisms, such activities have not been investigated so far for the lipid fraction of whey. Here, we have used an in vitro assay-based fractionation procedure to show that free fatty acids derived from whey cream specifically inhibit the germination of Candida albicans, a morphologic change associated with pathogenicity. Further fractionation by HPLC demonstrated that this activity can be mainly attributed to lauric acid, myristoleic acid, linoleic acid and arachidonic acid.
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Affiliation(s)
- Martin Clément
- Départment de Microbiologie et Immunologie, Université de Montréal, C.P. 6128, succ. Centre-ville, Montréal, QC, Canada
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566
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Kemppinen A, Kalo P. Quantification of triacylglycerols in butterfat by gas chromatography-electron impact mass spectrometry using molar correction factors for [M-RCOO]+ ions. J Chromatogr A 2006; 1134:260-83. [PMID: 16996071 DOI: 10.1016/j.chroma.2006.08.089] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2006] [Revised: 08/28/2006] [Accepted: 08/30/2006] [Indexed: 11/27/2022]
Abstract
A quantitative electron impact GC-MS method using molar correction factors (MCFs) for [M-RCOO]+ ions has been developed for determination of molecular species of triacylglycerols (TAGs). MCFs were determined by linear calibration for 226 ions of 104 TAG species with good reproducibility: on the average, coefficient of determination was 0.975 +/- 0.043 and 0.963 +/- 0.115 for saturated and unsaturated TAGs, respectively. The MCFs of the sn-1(3) regioisomers of short-chain TAGs were lower than those of sn-2 isomers indicating ca. 2-3-fold higher cleavage of butyroyl and caproyl groups from the primary positions than from the secondary position. The method enabled quantification of 139 and 135 individual TAG species of butterfat (BF) and interesterified butterfat, respectively, including several regioisomers of short-chain TAGs. The most abundant molecular species of the even-numbered TAGs in BF were butyroylpalmitoyloleoylglycerol (5.05 mol%), butyroyldipalmitoylglycerol (4.75 mol%), and palmitoyldioleoylglycerol (3.32 mol%). The method provides an alternative for elucidation of nutritional and technological properties of relatively saturated TAG mixtures.
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Affiliation(s)
- Asmo Kemppinen
- Department of Food Technology, FI-00014 University of Helsinki, Helsinki, Finland.
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567
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Amalaradjou MAR, Annamalai T, Marek P, Rezamand P, Schreiber D, Hoagland T, Venkitanarayanan K. Inactivation of escherichia coli O157:H7 in cattle drinking water by sodium caprylate. J Food Prot 2006; 69:2248-52. [PMID: 16995532 DOI: 10.4315/0362-028x-69.9.2248] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Escherichia coli O157:H7 is an important foodborne pathogen. Cattle serve as one of the major reservoirs of E. coli O157:H7, excreting the pathogen in feces. Environmental persistence of E. coli O157:H7 is critical in its epidemiology on farms, and the pathogen has been isolated from cattle water troughs. Thus, there is a need for an effective method for killing E. coli O157:H7 in cattle drinking water. In this study, the efficacy of sodium caprylate for killing E. coli O157:H7 in cattle drinking water was investigated. A four-strain mixture of E. coli O157:H7 was inoculated (6.0 log CFU/ml) into 100-ml samples of well water containing 0, 75, 100, or 120 mM sodium caprylate. Water samples containing 1% (wt/vol) bovine feces or feed also were included. The samples were incubated at 21 or 8 degrees C for 21 days. Water samples were analyzed for viable E. coli O157:H7 on days 0, 1, 3, 5, and 7 and weekly thereafter. Triplicate samples of each treatment and control were included, and the study was repeated twice. The magnitude of E. coli O157:H7 inactivation in water significantly increased (P < 0.01) with increases in caprylate concentration and storage temperature. At 120 mM, sodium caprylate completely inactivated E. coli O157:H7 in all the samples after 1 to 20 days, depending on the treatments. The presence of feces or feed also had a significant effect (P < 0.01) on the antibacterial property of caprylate; the presence of feces decreased the antibacterial effect, whereas addition of feed enhanced the effect. These results indicate that sodium caprylate is effective in killing E. coli O157:H7 in cattle drinking water, but detailed cattle palatability studies of water containing caprylate are necessary.
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568
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Talpur FN, Bhanger M, Khuhawar M. Comparison of fatty acids and cholesterol content in the milk of Pakistani cow breeds. J Food Compost Anal 2006. [DOI: 10.1016/j.jfca.2005.10.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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569
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Destaillats F, de Wispelaere M, Joffre F, Golay PA, Hug B, Giuffrida F, Fauconnot L, Dionisi F. Authenticity of milk fat by fast analysis of triacylglycerols. Application to the detection of partially hydrogenated vegetable oils. J Chromatogr A 2006; 1131:227-34. [PMID: 16893547 DOI: 10.1016/j.chroma.2006.07.040] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2006] [Revised: 07/14/2006] [Accepted: 07/17/2006] [Indexed: 10/24/2022]
Abstract
Detection of foreign fat in milk fat can be performed by analyzing triacylglycerols (TAGs) by gas-liquid chromatography (GLC) using the standardized methodology. The standard methodology recommends the use of a packed column, which allows the separation of milk TAGs according to their chain length (total carbon number). This procedure is not widely applied because these columns are not commercially available. This study describes a fast methodology by using a short apolar open-tubular capillary column. The developed experimental conditions can be used to obtain the chromatographic resolution required in the standardized procedure, and the separation of milk fat TAGs (C24 to C54) is achieved in less than 4 min. As indicated by the standardized method, the quantification was performed by calibration using the certified reference material CRM-519 butterfat as standard substance. The methodology was fully validated and relative repeatability values were compared with the values provided in the standardized procedure. The developed method was applied to detect adulteration of milk fat with partially hydrogenated vegetable oils (PHVOs). PHVOs contain variable amount of trans-18:1 acids and two different PHVOs having different trans-18:1 acid levels (13 and 38%) were added to milk fat at levels ranging from 5 to 30%. The obtained mixtures were analyzed by GLC and formulas established by the European Union were applied. Calculated S values indicated that PHVOs in milk fat could be analyzed at these levels. Approximate amounts of PHVOs added to the composite samples could be calculated using the standardized formula. The impact of adulteration of milk fat with PHVOs, which contains an important amount of trans-9 and trans-10 18:1 acid isomers, was investigated as a complementary analytical criteria. We showed in composite samples, that the trans-18:1 acid isomeric distributions are distinct when referenced to the original milk fat profile and that trans-9 18:1 acid isomer is a good indicator of the occurrence of PHVOs in milk fat. Our results showed clearly that a short apolar capillary column can be used instead of a packed-column and that the mathematical model developed for the detection of foreign fat was suitable to detect adulteration of milk fat with PHVOs.
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570
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Michalski MC, Januel C. Does homogenization affect the human health properties of cow's milk? Trends Food Sci Technol 2006. [DOI: 10.1016/j.tifs.2006.02.004] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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571
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Mele M, Buccioni A, Petacchi F, Serra A, Banni S, Antongiovanni M, Secchiari P. Effect of forage/concentrate ratio and soybean oil supplementation on milk yield, and composition from Sarda ewes. ACTA ACUST UNITED AC 2006. [DOI: 10.1051/animres:2006019] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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572
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Garnsworthy PC, Masson LL, Lock AL, Mottram TT. Variation of milk citrate with stage of lactation and de novo fatty acid synthesis in dairy cows. J Dairy Sci 2006; 89:1604-12. [PMID: 16606730 DOI: 10.3168/jds.s0022-0302(06)72227-5] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Citrate is a normal constituent of milk that affects milk-processing characteristics. It is an intermediate in the tricarboxylic acid cycle and plays an indirect role in fat synthesis by providing reducing equivalents in the form of NADPH. The objective of this study was to investigate variation in citrate with stage of lactation and de novo fatty acid synthesis, without confounding dietary effects. Twenty-four cows were fed the same diet, and milk citrate and fatty acids were determined over a 10-d period. Eight cows were in early lactation [13 +/- 1.8 d in milk (DIM; mean +/-standard error], 8 in midlactation (130 +/-4.6 DIM), and 8 in late lactation (283 +/-3.4 DIM). For cows in early, mid, and late lactation, milk yield was 34.4, 34.4, and 21.4 L/d [standard error of difference (SED) 1.78]; milk fat was 50.4, 40.3, and 41.4 g/L (3.68); milk citrate was 11.3, 9.7, and 10.1 mmol/L (0.64); the ratio of 4-14 C:18-20 C fatty acids was 0.9, 1.3, and 1.2 (0.07). Activity of the fatty acid synthase enzyme system (EC 2.3.1.85) was calculated as acetate used for chain elongation (ACE); ACE (mol/d) for cows in early, mid, and late lactation, was 7.3, 11.1, and 8.1 (SED 1.05). For individual cows, citrate (mmol/L) = 14.3 -0.44 xACE (r2 = 0.58). We propose that ACE provides a more accurate indication of synthase activity than do fatty acid ratios or yields. This study confirms the hypothesis that variation in milk citrate with stage of lactation is related to de novo synthesis of fatty acids and that the relationship is independent of diet and milk yield.
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Affiliation(s)
- P C Garnsworthy
- Division of Agricultural and Environmental Sciences, The University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, United Kingdom
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573
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Wright TC, Cant JP, Brenna JT, McBride BW. Acetyl CoA Carboxylase Shares Control of Fatty Acid Synthesis with Fatty Acid Synthase in Bovine Mammary Homogenate. J Dairy Sci 2006; 89:2552-8. [PMID: 16772574 DOI: 10.3168/jds.s0022-0302(06)72331-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The objectives of this research were to determine the flux control coefficients for acetyl CoA carboxylase and fatty acid synthase using an in vitro preparation of bovine mammary homogenate. For an enzyme to be considered rate limiting with the use of metabolic control analysis, its control coefficient would be equal to unity. The hypothesis for this experiment was that the control coefficient for acetyl CoA carboxylase was not equal to unity, and that this enzyme was not, therefore, the rate-limiting step. Mammary tissue was isolated from lactating Holstein cows at slaughter and frozen in liquid nitrogen. Tissue was ground, homogenized, and centrifuged to obtain a postmitochondrial supernatant for use in in vitro incubations containing labeled acetate. Specific inhibitors for acetyl CoA carboxylase and fatty acid synthase were used to fractionally inhibit de novo synthesis for the calculation of flux control coefficients. The composition of fatty acids synthesized in the absence of enzyme inhibitors was similar to the composition of fatty acids in the presence of inhibitors. Calculations following avidin inhibition of acetyl CoA carboxylase determined the flux control coefficient was 0.63 +/- 0.15, which means that 63% of the control of fatty acid synthesis is exerted by acetyl CoA carboxylase. The remaining control (37%) was from fatty acid synthase, which indicates a significant degree of control over the flux of acetate in de novo synthesis resides with this enzyme. The rate-limiting status ascribed to acetyl CoA carboxylase was not supported, because the flux control coefficient was less than unity. Metabolic control analysis, through its use of pathway product measurements, allows for potential interactions in the pathway such as feedback inhibition contribution to the flux control coefficients, which would not otherwise be considered in studies measuring enzyme kinetics with purified enzymes.
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Affiliation(s)
- T C Wright
- Department of Animal and Poultry Science, University of Guelph, Guelph, ON, Canada N1G 2W1
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574
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Ellis KA, Innocent G, Grove-White D, Cripps P, McLean WG, Howard CV, Mihm M. Comparing the Fatty Acid Composition of Organic and Conventional Milk. J Dairy Sci 2006; 89:1938-50. [PMID: 16702257 DOI: 10.3168/jds.s0022-0302(06)72261-5] [Citation(s) in RCA: 131] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
During a 12-mo longitudinal study, bulk-tank milk was collected each month from organic (n = 17) and conventional (n = 19) dairy farms in the United Kingdom. All milk samples were analyzed for fatty acid (FA) content, with the farming system type, herd production level, and nutritional factors affecting the FA composition investigated by use of mixed model analyses. Models were constructed for saturated fatty acids, the ratio of polyunsaturated fatty acids (PUFA) to monounsaturated fatty acids, total n-3 FA, total n-6 FA, conjugated linoleic acid, and vaccenic acid. The ratio of n-6:n-3 FA in both organic and conventional milk was also compared. Organic milk had a higher proportion of PUFA to monounsaturated fatty acids and of n-3 FA than conventional milk, and contained a consistently lower n-6:n-3 FA ratio (which is considered beneficial) compared with conventional milk. There was no difference between organic and conventional milk with respect to the proportion of conjugated linoleic acid or vaccenic acid. A number of factors other than farming system were identified which affected milk FA content including month of year, herd average milk yield, breed type, use of a total mixed ration, and access to fresh grazing. Thus, organic dairy farms in the United Kingdom produce milk with a higher PUFA content, particularly n-3 FA, throughout the year. However, knowledge of the effects of season, access to fresh grazing, or use of specific silage types could be used by producers to enhance the content of beneficial FA in milk.
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Affiliation(s)
- K A Ellis
- Division of Animal Production and Public Health, University of Glasgow Veterinary School, Bearsden Road, Bearsden, Glasgow, G61 1QH, UK.
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575
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Singh H. The milk fat globule membrane—A biophysical system for food applications. Curr Opin Colloid Interface Sci 2006. [DOI: 10.1016/j.cocis.2005.11.002] [Citation(s) in RCA: 196] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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576
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German JB, Dillard CJ. Composition, structure and absorption of milk lipids: a source of energy, fat-soluble nutrients and bioactive molecules. Crit Rev Food Sci Nutr 2006; 46:57-92. [PMID: 16403683 DOI: 10.1080/10408690590957098] [Citation(s) in RCA: 172] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Milkfat is a remarkable source of energy, fat-soluble nutrients and bioactive lipids for mammals. The composition and content of lipids in milkfat vary widely among mammalian species. Milkfat is not only a source of bioactive lipid components, it also serves as an important delivery medium for nutrients, including the fat-soluble vitamins. Bioactive lipids in milk include triacylglycerides, diacylglycerides, saturated and polyunsaturated fatty acids, and phospholipids. Beneficial activities of milk lipids include anticancer, antimicrobial, anti-inflammatory, and immunosuppression properties. The major mammalian milk that is consumed by humans as a food commodity is that from bovine whose milkfat composition is distinct due to their diet and the presence of a rumen. As a result of these factors bovine milkfat is lower in polyunsaturated fatty acids and higher in saturated fatty acids than human milk, and the consequences of these differences are still being researched. The physical properties of bovine milkfat that result from its composition including its plasticity, make it a highly desirable commodity (butter) and food ingredient. Among the 12 major milk fatty acids, only three (lauric, myristic, and palmitic) have been associated with raising total cholesterol levels in plasma, but their individual effects are variable-both towards raising low-density lipoproteins and raising the level of beneficial high-density lipoproteins. The cholesterol-modifying response of individuals to consuming saturated fats is also variable, and therefore the composition, functions and biological properties of milkfat will need to be re-evaluated as the food marketplace moves increasingly towards more personalized diets.
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Affiliation(s)
- J Bruce German
- Department of Food Science and Technology, University of California, Davis, CA, 95616, USA.
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577
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Cabiddu A, Addis M, Pinna G, Spada S, Fiori M, Sitzia M, Pirisi A, Piredda G, Molle G. The inclusion of a daisy plant (Chrysanthemum coronarium) in dairy sheep diet. 1: Effect on milk and cheese fatty acid composition with particular reference to C18:2 cis-9, trans-11. Livest Sci 2006. [DOI: 10.1016/j.livprodsci.2005.09.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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578
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Guy PA, Fenaille F. Contribution of mass spectrometry to assess quality of milk-based products. MASS SPECTROMETRY REVIEWS 2006; 25:290-326. [PMID: 16369930 DOI: 10.1002/mas.20074] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The vast knowledge of milk chemistry has been extensively used by the dairy manufacturing industry to develop and optimize the modern technology required to produce high-quality milk products to which we are accustomed. A thorough understanding of the chemistry of milk and its numerous components is essential for designing processing equipment and conditions needed for the manufacture and distribution of high-quality dairy products. Knowledge and application of milk chemistry is also indispensable for fractionating milk into its principal components for use as functional and nutritional ingredients by the food industry. For all these reasons, powerful analytical methods are required. Because of the complexity of the milk matrix, mass spectrometry, coupled or not to separation techniques, constitutes a key tool in this area. In the present manuscript, we review the contribution and potentialities of mass spectrometry-based techniques to assess quality of milk-based products.
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Affiliation(s)
- Philippe A Guy
- Department of Quality and Safety Assurance, Nestlé Research Center, Lausanne, Switzerland.
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579
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Mosley EE, Shafii Dagger B, Moate PJ, McGuire MA. cis-9, trans-11 conjugated linoleic acid is synthesized directly from vaccenic acid in lactating dairy cattle. J Nutr 2006; 136:570-5. [PMID: 16484526 DOI: 10.1093/jn/136.3.570] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The utilization of (13)C-labeled vaccenic acid (VA) by lactating dairy cows to synthesize cis-9, trans-11 conjugated linoleic acid (CLA) was investigated. Primiparous ruminally cannulated Holstein cows (n = 3) were abomasally infused with 1.5 g of VA-1-(13)C. Blood and milk samples were taken frequently before and after VA infusion. Milk and plasma lipid were extracted using chloroform:methanol. Plasma lipid was separated into triacylglycerol (TG), cholesterol ester (CE), phospholipid (PL), nonesterified fatty acid (NEFA), and mono- and diacylglycerol (MDG) fractions. Lipid was methylated, converted to dimethyl disulfide and Diels-Alder adducts, and analyzed by GC-MS. Increased enrichment of (13)C was determined using a 2-sample t test for each sample time compared with -24 h, with significance declared at P < 0.05. Enrichment in milk fat VA was detected at 4 (3.0%), 8 (8.3%), 12 (4.1%), 16 (2.2%), and 20 h (0.8%). Enrichment in VA was also detected in plasma TG, NEFA, PL, and MDG. Enrichment in milk fat cis-9, trans-11 CLA, the Delta9-desaturase product of VA, was detected at 4 (2.6%), 8 (6.6%), 12 (3.4%), 16 (1.7%), and 24 h (0.7%). Enrichment was not detected in cis-9, trans-11 CLA for any plasma lipid fraction. Modeling of the data showed the exponential decay in (13)C enrichment over time for both VA and cis-9, trans-11 CLA in milk fat. Conversion of dietary VA to cis-9, trans-11 CLA endogenously was confirmed with the mammary gland being the primary site of Delta9-desaturase activity; approximately 80% of milk fat cis-9, trans-11 CLA originated from VA.
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Affiliation(s)
- Erin E Mosley
- Department of Animal and Veterinary Science, College of Agricultural and Life Sciences, University of Idaho, Moscow, ID 83844-2330, USA
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580
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Nikolova D, Antonova D, Marekov I, Nikolova-Damyanova B. Bis-methylene-interrupted octadecadienoic fatty acids in Bulgarian bovine butter fats. EUR J LIPID SCI TECH 2006. [DOI: 10.1002/ejlt.200500297] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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581
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Michalski MC, Soares AF, Lopez C, Leconte N, Briard V, Geloen A. The supramolecular structure of milk fat influences plasma triacylglycerols and fatty acid profile in the rat. Eur J Nutr 2006; 45:215-24. [PMID: 16432662 DOI: 10.1007/s00394-006-0588-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2005] [Accepted: 12/15/2005] [Indexed: 10/25/2022]
Abstract
BACKGROUND The digestion fate of milk fat depending on its supramolecular structure for a given dairy product composition has rarely been studied. AIM OF THE STUDY To highlight differences of lipid digestion, we measured (i) the plasma triacylglycerol and cholesterol concentrations and (ii) the total plasma fatty acid profile of fasted rats force-fed with different dairy preparations; the three creams and the unemulsified preparation had a similar composition with different and controlled fat suprastructures. METHODS All preparations, manufactured in the laboratory from a given milk batch, contained 205 +/- 3 g . kg(-1) fat that was either fed (i) unemulsified consecutively to the skim milk phase, or as a cream with the following fat globule structures: (ii) native milk fat globules of approximately 4 microm covered with the native milk fat globule membrane (MFGM), (iii) small native milk fat globules of approximately 2 microm selected from the latter by microfiltration and covered by the MFGM, or (iv) fine homogenized fat droplets of approximately 1 microm covered mainly with caseins. RESULTS The plasma triacylglycerol appearance was delayed for the creams compared with the rapid onset for the unemulsified preparation. At 90 and 180 min after feeding, the plasma triacylglycerol enrichment was significantly lower for the homogenized cream than for the unemulsified preparation. At 120 min after feeding, triacylglycerol enrichment was significantly lower for each cream than for the unemulsified preparation. At 180 min after feeding, the plasma relative enrichment in C12, C14, C15, C16 and C18:1 n-9 fatty acids was significantly lower for the homogenized cream than for unemulsified fat and regular cream. CONCLUSIONS Global lipid digestion based on plasma triacylglycerol enrichment and relative enrichments in some fatty acids was decreased with small homogenized milk fat droplets compared to unemulsified milk fat. These data show that dairy products with the same composition but varying in fat supramolecular structure result in different kinetics of lipid digestion, which could be of health concern.
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Affiliation(s)
- Marie-Caroline Michalski
- Mécanismes Moléculaires du Diabète, INRA UMR 1235-INSERM U 449, Faculté de Médecine R. Laënnec, Université Claude Bernard-Lyon I, 8, rue Guillaume Paradin, 69372, Lyon cedex 08, France.
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582
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Fontecha J, Goudjil H, Ríos J, Fraga M, Juárez M. Identity of the major triacylglycerols in ovine milk fat. Int Dairy J 2005. [DOI: 10.1016/j.idairyj.2004.11.013] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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583
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Addis M, Cabiddu A, Pinna G, Decandia M, Piredda G, Pirisi A, Molle G. Milk and Cheese Fatty Acid Composition in Sheep Fed Mediterranean Forages with Reference to Conjugated Linoleic Acid cis-9,trans-11. J Dairy Sci 2005; 88:3443-54. [PMID: 16162517 DOI: 10.3168/jds.s0022-0302(05)73028-9] [Citation(s) in RCA: 127] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Two experiments were undertaken to evaluate the effect on milk and cheese fatty acid composition of feeding different fresh forages to dairy sheep both in winter (experiment 1, growing stage of the forages, early lactating ewes) and in spring (experiment 2, reproduction stage of the forages, midlactating ewes). Four forage species were compared: annual ryegrass (RY, Lolium rigidum Gaudin), sulla (SU, Hedysarum coronarium L.), burr medic (BM, Medicago polymorpha L.), and a daisy forb (CH, Chrysanthemum coronarium L.). The forages were cut twice daily and offered ad libitum to 4 replicate groups of Sarda dairy sheep (groups RY, SU, BM, and CH). The CH forage was particularly rich in linoleic acid in both periods, whereas BM and SU forages were rich in linolenic acid in winter and spring, respectively. Milk fatty acid composition was affected by the forage in both experiments. Milk conjugated linoleic acid and vaccenic acid contents were higher in CH and BM groups (winter) and CH group (spring) than in the other groups. No differences were observed when comparing fatty acid profile between milk, 1-d-old cheeses, and 60-d-old cheeses within experimental groups, suggesting that the fatty acid recovery rates during cheese making and ripening were not affected by the feeding regimens. After stepwise discriminant analyses of the pooled data, the milks and cheeses sourced in the different feeding regimens differed among them. Based on these results, we conclude that it is possible to manipulate the fatty acid profile of sheep dairy produce to maximize the content of beneficial fatty acids by the use of appropriate fresh forage-based regimens.
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Affiliation(s)
- M Addis
- Istituto Zootecnico e Caseario per la Sardegna, Loc. Bonassai, 07040, Italy.
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584
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Nair MKM, Joy J, Vasudevan P, Hinckley L, Hoagland TA, Venkitanarayanan KS. Antibacterial Effect of Caprylic Acid and Monocaprylin on Major Bacterial Mastitis Pathogens. J Dairy Sci 2005; 88:3488-95. [PMID: 16162522 DOI: 10.3168/jds.s0022-0302(05)73033-2] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Bovine mastitis is the most significant economic drain on the worldwide dairy industry. Concerns regarding poor cure rates, emergence of bacterial resistance, and residues in milk necessitate development of alternative therapeutic approaches to antibiotics for treatment of mastitis. A variety of free fatty acids and their monoglycerides have been reported to exert antimicrobial activity against a wide range of microorganisms. The objective of our study was to examine the efficacy of caprylic acid, a short-chain fatty acid, and its monoglyceride, monocaprylin, to inactivate common mastitis pathogens, including Streptococcus agalactiae, Streptococcus dysgalactiae, Streptococcus uberis, Staphylococcus aureus, and Escherichia coli. Milk samples containing 50 mM or 100 mM caprylic acid, and 25 mM or 50 mM monocaprylin were inoculated separately with a 3-isolate mixture of each of the 5 pathogens, and incubated at 39 degrees C. Populations of surviving bacteria were determined at 0 min, 1 min, 6 h, 12 h, and 24 h of incubation. Both caprylic acid and monocaprylin reduced all 5 pathogens by >5.0 log cfu/mL after 6 h of incubation. Among the bacterial species tested, Strep. agalactiae, Strep. dysgalactiae, and Strep. uberis were most sensitive, and E. coli was most tolerant to caprylic acid and monocaprylin. Results of this study indicate that caprylic acid and monocaprylin should be evaluated as alternatives or adjuncts to antibiotics as intra-mammary infusion to treat bovine mastitis.
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Affiliation(s)
- M K M Nair
- Department of Animal Science, Unit 4040, University of Connecticut, Storrs 06269, USA
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585
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Nair MKM, Abouelezz H, Hoagland T, Venkitanarayanan K. Antibacterial effect of monocaprylin on Escherichia coli O157:H7 in apple juice. J Food Prot 2005; 68:1895-9. [PMID: 16161689 DOI: 10.4315/0362-028x-68.9.1895] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The antibacterial effect of low concentrations of monocaprylin on Escherichia coli O157:H7 in apple juice was investigated. Apple juice alone (control) or containing 2.5 mM (0.055%) or 5 mM monocaprylin was inoculated with a five-strain mixture of E. coli O157:H7 at approximately 6.0 log CFU/ml. The juice samples were stored at 23 or 4 degrees C for 14 or 21 days, respectively, and the population of E. coli O157:H7 was determined on tryptic soy agar plates supplemented with 0.6% yeast extract. At both storage temperatures, the population of E. coli O157:H7 in monocaprylin-supplemented juice samples was significantly lower (P < 0.05) than that in the control samples. The concentration of monocaprylin and the storage temperature had a significant effect on the inactivation of E. coli O157:H7 in apple juice. Monocaprylin at 5 mM was significantly more effective than 2.5 mM monocaprylin for killing E. coli O157:H7 in apple juice. Inactivation of E. coli O157:H7 by monocaprylin was more pronounced in juice stored at 23 degrees C than in the refrigerated samples. Results of this study indicated that monocaprylin is effective for killing E. coli O157:H7 in apple juice, but detailed sensory studies are needed to determine the organoleptic properties of apple juice containing monocaprylin.
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Affiliation(s)
- Manoj Kumar Mohan Nair
- Department of Animal Science, Unit 40, University of Connecticut, 3636 Horsebarn Hill Road Extension, Storrs, Connecticut 06269, USA
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586
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Soita HW, Fehr M, Christensen DA, Mutsvangwa T. Effects of Corn Silage Particle Length and Forage:Concentrate Ratio on Milk Fatty Acid Composition in Dairy Cows Fed Supplemental Flaxseed. J Dairy Sci 2005; 88:2813-9. [PMID: 16027195 DOI: 10.3168/jds.s0022-0302(05)72961-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
This study aimed to evaluate the effects of length of chop of corn silage and forage:concentrate ratio (F:C) on performance and milk fatty acid profiles in dairy cows supplemented with flaxseed. Our hypothesis was that decreasing forage particle length and F:C ratio would increase unsaturated fatty acid flow to the small intestine and subsequent transfer of these unsaturated fatty acids into milk. Eight Holstein cows (648.1 +/- 71.5 kg body weight; 109.6 +/-43.6 days in milk) were used in a replicated 4 x4 Latin square design with 21-d periods and a 2 x2 factorial arrangement of dietary treatments. Dietary factors were: 1) F:C ratios (dry matter basis) of 55:45 and 45:55; and 2) corn silage particle lengths of 9.52 and 19.05 mm. All experimental cows received 1 kg of flaxseed to substitute for 1 kg of a rolled barley grain-based concentrate daily. Diets were fed twice daily as a total mixed ration. Corn silage particle length and F:C ratio had no effect on dry matter intake, milk yield, and milk composition; however, feeding short cut corn silage depressed milk protein yield. Significant particle size xF:C ratio interactions were observed for milk fat proportions of C(16:0), C(18:1) cis-9, and C(18:2) cis-9, trans-11 (a conjugated linoleic acid isomer). At short corn silage particle size, decreasing F:C ratio depressed milk fat proportion of C(16:0). Conversely, feeding short corn silage at high F:C ratio increased the proportion of C(18:1) cis-9 and C(18:2) cis-9, trans-11 in milk fat. The milk fat proportion of C(18:2) trans-10, cis-12, a conjugated linoleic acid isomer that is associated with milk fat depression, was not affected by dietary treatment. Our results show that corn silage particle length and F:C ratio influence milk fatty acid profiles in dairy cows fed supplemental flaxseed as a source of polyunsaturated fatty acids.
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Affiliation(s)
- H W Soita
- Department of Animal and Poultry Science, University of Saskatchewan, Saskatoon, Canada S7N 5A8
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587
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Cabiddu A, Decandia M, Addis M, Piredda G, Pirisi A, Molle G. Managing Mediterranean pastures in order to enhance the level of beneficial fatty acids in sheep milk. Small Rumin Res 2005. [DOI: 10.1016/j.smallrumres.2005.05.005] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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588
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Vasudevan P, Marek P, Nair M, Annamalai T, Darre M, Khan M, Venkitanarayanan K. In Vitro Inactivation of Salmonella Enteritidis in Autoclaved Chicken Cecal Contents by Caprylic Acid. J APPL POULTRY RES 2005. [DOI: 10.1093/japr/14.1.122] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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589
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Michalski MC, Briard V, Desage M, Geloen A. The dispersion state of milk fat influences triglyceride metabolism in the rat. Eur J Nutr 2005; 44:436-44. [PMID: 16200479 DOI: 10.1007/s00394-005-0551-1] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2004] [Accepted: 12/10/2004] [Indexed: 11/26/2022]
Abstract
BACKGROUND Milk fat, which has different structures in the various dairy products, is a major and controversial lipid source in the Western diet. However, information about the digestion fate of milk fat depending on its supramolecular structure for a given composition is scarce. AIM OF THE STUDY In this study, 13CO2 breath tests were performed with fasted rats force-fed different dairy preparations of similar composition but differing in fat suprastructure in order to highlight differences of general lipid metabolism. METHODS Each preparation consisted of a NaCl solution, anhydrous milk fat labelled with a 13C mixed triacylglycerol, casein (as native phosphocaseinate powder with some lactose), and dipalmitoylphosphatidylcholine. Milk fat was either fed (i) unemulsified consecutively to the aqueous phase, or emulsified as (ii) coarse droplets of approximately 10 microm covered mainly with the phospholipid, or (iii-iv) fine droplets of approximately 1 microm covered mainly with casein, force-fed either in the liquid state or in a semi-crystallized state. 13C abundance in expired air samples was measured by isotope ratio mass spectrometry; results were expressed as 13C enrichment and were submitted to an ANOVA analysis. RESULTS The 13CO2 excretion curves of the unemulsified preparation and the coarse emulsion were similar and presented a sharp peak, both significantly different from the fine emulsion curves characterized by a nearly linear cumulative recovery. The crystalline state of the fine emulsion droplets and the viscosity of these emulsions did not affect significantly their excretion curves. The lipid metabolization (indicated by the 13C recovery) was significantly slower for the fine droplets coated with casein than for the large droplets coated with the phospholipid and the unemulsified fat. For the latter, a single 13C peak rapidly appeared, while for small droplets coated with caseins, 13C excretion was continuous up to 6 h. CONCLUSIONS Global lipid metabolism based on oxidation to CO2 was decreased with smaller compared to larger emulsified milk fat particles with different coatings. These data support the concept that dairy products with different fat suprastructures are digested and metabolized differently.
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590
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Fauquant C, Briard V, Leconte N, Michalski MC. Differently sized native milk fat globules separated by microfiltration: fatty acid composition of the milk fat globule membrane and triglyceride core. EUR J LIPID SCI TECH 2005. [DOI: 10.1002/ejlt.200401063] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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591
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Innis S. Chapter 10 Essential fatty acid metabolism during early development. BIOLOGY OF GROWING ANIMALS 2005. [DOI: 10.1016/s1877-1823(09)70017-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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592
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Palmquist DL, Lock AL, Shingfield KJ, Bauman DE. Biosynthesis of conjugated linoleic acid in ruminants and humans. ADVANCES IN FOOD AND NUTRITION RESEARCH 2005; 50:179-217. [PMID: 16263431 DOI: 10.1016/s1043-4526(05)50006-8] [Citation(s) in RCA: 170] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Affiliation(s)
- Donald L Palmquist
- Department of Animal Sciences, Ohio Agricultural Research and Development Center/The Ohio State University, Wooster, Ohio 44691, USA
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593
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Nair MKM, Joy J, Venkitanarayanan KS. Inactivation of Enterobacter sakazakii in reconstituted infant formula by monocaprylin. J Food Prot 2004; 67:2815-9. [PMID: 15633694 DOI: 10.4315/0362-028x-67.12.2815] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Enterobacter sakazakii is an emerging pathogen that causes meningitis, bacteremia, sepsis, and necrotizing enterocolitis in neonates and children, with a mortality rate of 14%. Epidemiological studies have implicated dried infant formula as the principal source of the pathogen. Caprylic acid is a natural eight-carbon fatty acid present in breast milk and bovine milk and is approved as generally recognizable as safe by the U.S. Food and Drug Administration. The objective of this study was to determine the antibacterial effect of monocaprylin (monoglyceride ester of caprylic acid) on E. sakazakii in reconstituted infant formula. A five-strain mixture of E. sakazakii was inoculated into 10-ml samples of reconstituted infant formula (at 6.0 log CFU/ml) followed by 0, 25, or 50 mM (1%) monocaprylin. The samples were incubated at 37 or 23 degrees C for 0, 1, 6, and 24 h and at 8 or 4 degrees C for 0, 6, 24, and 48 h, and the surviving populations of E. sakazakii at each sampling time were counted. The treatments containing monocaprylin significantly reduced the population of E. sakazakii (P < 0.05) compared with the controls. Monocaprylin (50 mM) reduced the pathogen by >5 log CFU/ml by 1 h of incubation at 37 or 23 degrees C and by 24 h of incubation at 8 or 4 degrees C. Results indicate that monocaprylin could potentially be used to inactivate E. sakazakii in reconstituted infant formula; however, sensory studies are warranted before its use can be recommended.
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Affiliation(s)
- Manoj Kumar Mohan Nair
- Department of Animal Science, Unit-4040, University of Connecticut, Storrs, Connecticut 06269, USA
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594
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Silveira T, Fonseca L, Cançado S, Ferraz V. Comparação entre os métodos de referência e a análise eletrônica na determinação da composição do leite bovino. ARQ BRAS MED VET ZOO 2004. [DOI: 10.1590/s0102-09352004000600013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Avaliou-se a metodologia de determinação da composição do leite por meio de analisador de infravermelho, utilizando-se 48 amostras individuais de leite de vacas da raça Holandesa e cinco amostras de leite de conjunto. A média dos resultados para gordura, proteína, lactose e sólidos totais das amostras individuais foram, respectivamente, 3,8%, 3,3%, 4,6% e 12,4%, usando-se metodologia de referência e 3,8%, 3,3%, 4,5% e 12,4%, usando-se equipamento eletrônico. Para amostras de tanque, as médias foram 3,9% e 4,0% para gordura, 3,2% e 3,2% para proteína, 4,7% e 4,6% para lactose e 12,6% e 12,6% para sólidos totais, respectivamente, para análises feitas por métodos de referência e por analisador de infravermelho. Não houve diferença (P>0,05) entre os valores das duas análises. Foi avaliada a qualidade das amostras-padrão canadense e americano, determinando-se os teores de gordura, proteína, lactose e sólidos totais por métodos de referência. Os resultados foram comparados com os valores declarados no laudo de análise das amostras, emitidos pelo laboratório fornecedor.
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595
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Michalski MC, Ollivon M, Briard V, Leconte N, Lopez C. Native fat globules of different sizes selected from raw milk: thermal and structural behavior. Chem Phys Lipids 2004; 132:247-61. [PMID: 15555609 DOI: 10.1016/j.chemphyslip.2004.08.007] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2004] [Revised: 06/25/2004] [Accepted: 08/13/2004] [Indexed: 10/26/2022]
Abstract
The aim of this study was to characterize differences in the thermal and structural behavior between different sized native milk fat globules. A novel microfiltration process permits the selection of native small fat globules (SFG, 1-3 microm) and large fat globules (LFG, >5 microm) in raw milk, that were analyzed by X-ray diffraction (XRD) coupled to differential scanning calorimetry (DSC). There were no major differences in triglyceride crystalline structures between SFG and LFG, after eliminating thermal history and the influence of cooling rates. The three main 3L and 2L crystalline structures appearing under slow cooling existed regardless of globule size. The supercooling increased for the SFG, mainly due to heterogeneous nucleation in winter milk, and also to compositional variations in spring milk. Differences appeared regarding stabilized crystalline forms at 20 degrees C and subsequent cooling: the SFG contained less 2L triglyceride structures than the LFG. These results can be important in dairy manufactures using tempering periods.
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Affiliation(s)
- Marie-Caroline Michalski
- Science et Technologie du Lait et de l'OEuf, UMR INRA 1253, 65 rue de Saint-Brieuc, 35042 Rennes Cedex, France.
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596
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Lock AL, Bauman DE. Modifying milk fat composition of dairy cows to enhance fatty acids beneficial to human health. Lipids 2004; 39:1197-206. [PMID: 15736916 DOI: 10.1007/s11745-004-1348-6] [Citation(s) in RCA: 354] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
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 delta9-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 delta9-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.
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Affiliation(s)
- Adam L Lock
- Department of Animal Science, Cornell University, Ithaca, New York 14853, USA
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597
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Nair MKM, Vasudevan P, Hoagland T, Venkitanarayanan K. Inactivation of Escherichia coli O157:H7 and Listeria monocytogenes in milk by caprylic acid and monocaprylin. Food Microbiol 2004. [DOI: 10.1016/j.fm.2004.01.003] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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598
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Noh SK, Koo SI. Milk sphingomyelin is more effective than egg sphingomyelin in inhibiting intestinal absorption of cholesterol and fat in rats. J Nutr 2004; 134:2611-6. [PMID: 15465755 DOI: 10.1093/jn/134.10.2611] [Citation(s) in RCA: 154] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
We reported previously that egg sphingomyelin (SM) inhibits the intestinal absorption of cholesterol and fat in rats. This study was conducted to compare the relative efficiencies of milk and egg SM in inhibiting intestinal absorption of cholesterol and other lipids. Adult male rats with lymph cannulae were infused at 3.0 mL/h for 8 h via a duodenal catheter with a lipid emulsion (451.7 micromol triolein, 20.7 micromol cholesterol, 33.3 kBq (14)C-cholesterol, 3.1 micromol alpha-tocopherol, and 396.0 micromol sodium taurocholate in 24 mL PBS, pH, 6.5), without SM (controls), or with 80.0 micromol egg SM or milk SM. The lymphatic absorptions of (14)C-cholesterol were significantly lower in rats infused with milk SM (19.5 +/- 1.4% dose) and egg SM (24.4 +/- 1.9% dose) than in those infused with no SM (37.6 +/- 1.8% dose). In addition, the lymphatic outputs of fatty acids and phospholipid were significantly lowered by milk and egg SM. Similarly, the absorption of alpha-tocopherol also was decreased by milk SM (13.6 +/- 1.7% dose) and egg SM (18.3 +/- 2.4% dose) compared with controls (27.0 +/- 1.8% dose). Total lymphatic SM output was not affected by egg SM, but markedly decreased by milk SM, relative to controls. The results indicate that both milk and egg SM markedly inhibit the absorption of cholesterol, fat, and other lipids. However, milk SM is a more potent inhibitor than egg SM. The strong inhibitory effect of milk SM may be associated with the higher degree of saturation and longer chain length of its fatty acyl groups, which may slow the rate of luminal lipolysis, micellar solubilization, and transfer of micellar lipids to the enterocyte.
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Affiliation(s)
- Sang K Noh
- Department of Nutritional Sciences, University of Connecticut, Storrs, CT 06269, USA
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599
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Fagan P, Wijesundera C. Liquid chromatographic analysis of milk phospholipids with on-line pre-concentration. J Chromatogr A 2004; 1054:241-9. [PMID: 15553150 DOI: 10.1016/j.chroma.2004.04.051] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Two methods have been developed for the analysis of bovine milk phospholipid (PL) classes by NP-HPLC with evaporative light scattering detection. In the first method, a PVA-Sil guard column was used for the rapid determination of the major milk PL, phosphatidylethathanolamine (PE), phosphatidylcholine (PC) and sphingomyelin (SM). In the second method, the guard column was used to pre-concentrate the PL, which were then transferred on-line onto a PVA-Sil analytical column by the use of column switching valves. This enabled separation of complete milk PL, including phosphatidylinositol (PI), phosphatidylserine (PS) and lysophosphatidylcholine (LPC).
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Affiliation(s)
- Peter Fagan
- Food Science Australia, Private Bag 16, Werribee 3030, Vic, Australia.
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Momchilova S, Tsuji K, Itabashi Y, Nikolova-Damyanova B, Kuksis A. Resolution of triacylglycerol positional isomers by reversed-phase high-performance liquid chromatography. J Sep Sci 2004; 27:1033-6. [PMID: 15352724 DOI: 10.1002/jssc.200401746] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The ability of reversed-phase high-performance liquid chromatography (RP-HPLC) to separate some positionally isomeric disaturated and monounsaturated triacylglycerols (TAGs) as intact species is demonstrated for the first time. Mobile phases of acetonitrile modified with methanol, ethanol, 2-propanol, 1-propanol, 1-butanol, acetone, or dichloromethane were tested for the separation of POP-PPO, PLP-PPL, PEP-PPE, and PDP-PPD (P-palmitic, O-oleic, L-linoleic, E-eicosapentaenoic, D-docosahexaenoic acid residue) on a single RP-HPLC column. The resolution improved with increasing number of double bonds in the acyl residues. While POP and PPO were only partially resolved, PDP and PPD were fully separated with all tested mobile phases, except those containing methanol. Also separated were the four TAGs having the same equivalent carbon number (ECN = 42), PEP, PPE, PDP, and PPD, on a single RP-HPLC column with mobile phase acetonitrile-2-propanol (70:30, v/v) at 0.8 mL/min. In all cases the isomer with the unsaturated acyl residue in either 1- or 3-position was retained more strongly than the respective 2-isomer.
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Affiliation(s)
- Svetlana Momchilova
- Graduate School of Fisheries Sciences, Hokkaido University, Hakodate 041-8611, Japan
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