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Hewa Nadugala B, Hepworth G, Mazzonetto M, Nebl T, Pagel CN, Raynes JK, Ranadheera CS, Logan A. Effect of composition, casein genetic variants and glycosylation degree on bovine milk whipping properties. Food Res Int 2024; 179:113949. [PMID: 38342518 DOI: 10.1016/j.foodres.2024.113949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2023] [Revised: 12/21/2023] [Accepted: 01/02/2024] [Indexed: 02/13/2024]
Abstract
This study investigated the individual and combined effects of ĸ-Casein (ĸ-CN; AA, AB, BB), β-Casein (β-CN; A1A1, A1A2, A2A2) and high and low ratios of glycosylated ĸ-CN to total ĸ-CN, referred to as the glycosylation degree (GD), on bovine cream whipping properties. The genetic variants of individual cows were identified using reversed-phase high-performance liquid chromatography (RP-HPLC) and verified through liquid chromatography-mass spectrometry (LC-MS). A previously discovered relationship between days-in-milk and GD was validated and used to obtain high and low GD milk. Whipped creams were created through the mechanical agitation of fat standardised cream from milk of different ĸ-CN, β-CN, and GD combinations, and whipping properties (the ability to whip, overrun, whipping time and firmness) were evaluated. No significant correlation was measured in whipping properties for cream samples from milks with different ĸ-CN and β-CN genetic variants. However, 80 % of samples exhibiting good whipping properties (i.e., the production of a stiffened peak) were from milk with low GD suggesting a correlation between whipping properties and levels of glycosylation. Moreover, cream separated from skim milk of larger casein micelle size showed superior whipping properties with shorter whipping times (<5 min), and higher firmness and overrun. Milk fat globule (MFG) size, on the other hand, did not affect whipping properties. Results indicate that the GD of κ-CN and casein micelle size may play a role in MFG adsorption at the protein and air interface of air bubbles formed during whipping; hence, they govern the dynamics of fat network formation and influencing whipping properties.
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Affiliation(s)
- Barana Hewa Nadugala
- School of Agriculture, Food & Ecosystem Sciences, Faculty of Science, University of Melbourne, VIC 3010, Australia; CSIRO Agriculture and Food, Werribee, Victoria 3030, Australia.
| | - Graham Hepworth
- Statistical Consulting Centre, The University of Melbourne, Parkville, Victoria 3010, Australia.
| | | | - Tom Nebl
- Biology Group, Biomedical Manufacturing Program, CSIRO, Clayton, VIC 3168, Australia.
| | - Charles N Pagel
- Melbourne Veterinary School, Faculty of Science, The University of Melbourne, VIC 3010, Australia.
| | | | - C S Ranadheera
- School of Agriculture, Food & Ecosystem Sciences, Faculty of Science, University of Melbourne, VIC 3010, Australia.
| | - Amy Logan
- CSIRO Agriculture and Food, Werribee, Victoria 3030, Australia.
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Thesbjerg MN, Johansen M, Larsen LB, Poulsen NA. Differences in post-translational modifications of proteins in milk from early and mid-lactation dairy cows as studied using total ion chromatograms from LC-ESI/MS. Int Dairy J 2021. [DOI: 10.1016/j.idairyj.2021.105262] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Xu W, van Knegsel A, Saccenti E, van Hoeij R, Kemp B, Vervoort J. Metabolomics of Milk Reflects a Negative Energy Balance in Cows. J Proteome Res 2020; 19:2942-2949. [PMID: 32633519 PMCID: PMC7426013 DOI: 10.1021/acs.jproteome.9b00706] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
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Dairy
cows can experience a negative energy balance (NEB) in early
lactation when feed intake is too low to meet the energy requirements
for body maintenance and milk production. Metabolic changes occur
in mammary gland cells of animals experiencing a negative energy balance.
We studied these metabolic changes in milk samples from dairy cows
in relation to energy balance status using liquid chromatography–mass
spectrometry (QQQ-LC–MS) and nuclear magnetic resonance (1H NMR). NMR and LC–MS techniques are complementary
techniques that enabled a comprehensive overview of milk metabolites
in our study. Energy balance and milk samples were obtained from 87
dairy cows. A total of 55 milk metabolites were reliably detected,
of which 15 metabolites were positively correlated to energy balance
and 20 were negatively correlated to energy balance. Cows in NEB produced
more milk with increased milk fat yield and higher concentrations
of citrate, cis-aconitate, creatinine, glycine, phosphocreatine,
galactose-1-phosphate, glucose-1-phosphate, UDP-N-acetyl-galactosamine, UDP-N-acetyl-glucosamine,
and phosphocholine but lower concentrations of choline, ethanolamine,
fucose, N-acetyl-neuraminic acid, N-acetyl-glucosamine, and N-acetyl-galactosamine.
During NEB, we observed an increased leakage of cellular content,
increased synthesis of nucleic acids and cell membrane phospholipids,
an increase in one-carbon metabolic processes, and an increase in
lipid-triglyceride anabolism. Overall, both apoptosis combined with
cellular renewal is paramount in the mammary gland in cows in NEB.
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Affiliation(s)
- Wei Xu
- Adaptation Physiology Group, Wageningen University & Research, Wageningen 6708 PB, the Netherlands.,Laboratory of Biochemistry, Wageningen University & Research, Wageningen 6708 PB, the Netherlands
| | - Ariette van Knegsel
- Adaptation Physiology Group, Wageningen University & Research, Wageningen 6708 PB, the Netherlands
| | - Edoardo Saccenti
- Systems and Synthetic Biology, Wageningen University & Research, Wageningen 6708 PB, the Netherlands
| | - Renny van Hoeij
- Adaptation Physiology Group, Wageningen University & Research, Wageningen 6708 PB, the Netherlands
| | - Bas Kemp
- Adaptation Physiology Group, Wageningen University & Research, Wageningen 6708 PB, the Netherlands
| | - Jacques Vervoort
- Laboratory of Biochemistry, Wageningen University & Research, Wageningen 6708 PB, the Netherlands
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Li S, Ye A, Singh H. Seasonal variations in composition, properties, and heat-induced changes in bovine milk in a seasonal calving system. J Dairy Sci 2019; 102:7747-7759. [PMID: 31326173 DOI: 10.3168/jds.2019-16685] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 05/23/2019] [Indexed: 11/19/2022]
Abstract
We determined seasonal variations in the composition and characteristics of bovine milk, as well as heat-induced changes in the physicochemical properties of the milk, in a typical seasonal-calving New Zealand herd over 2 full milking seasons. Fat, protein, and lactose contents varied consistently during the year in patterns similar to those of the lactation cycle. Seasonality also had significant effects on milk calcium, ionic calcium, fat globule size, buffering capacity, and ethanol stability, but not on casein micelle size. The ratio of casein to total protein did not vary significantly over the season, but late-season milk had the highest content of glycosylated κ-casein (G-κ-CN) and the lowest content of α-lactalbumin in both years. We observed significant between-year effects on protein, total calcium, ionic calcium, pH, and casein:total protein ratio, which might have resulted from different somatic cell counts in the 2 years. Compared with heating at 90°C for 6 min, UHT treatment (140°C for 5 s) induced greater dissociation of κ-casein, a similar extent of whey protein denaturation, a lower extent of whey protein-casein micelle association, and a larger increase in casein micelle size. Indeed, UHT treatment might have triggered significant dissociation of G-κ-CN, resulting in aggregation among the casein micelles and increased apparent mean casein micelle diameter. Seasonality had significant effects on the partitioning of G-κ-CN between the micelle and the serum phase, the extent of whey protein-casein micelle association under both heating conditions, and the casein micelle size of the UHT milk.
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Affiliation(s)
- Siqi Li
- Riddet Institute, Massey University, Private Bag 11 222, Palmerston North 4442, New Zealand
| | - Aiqian Ye
- Riddet Institute, Massey University, Private Bag 11 222, Palmerston North 4442, New Zealand.
| | - Harjinder Singh
- Riddet Institute, Massey University, Private Bag 11 222, Palmerston North 4442, New Zealand
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Poulsen N, Jensen H, Larsen L. Factors influencing degree of glycosylation and phosphorylation of caseins in individual cow milk samples. J Dairy Sci 2016; 99:3325-3333. [DOI: 10.3168/jds.2015-10226] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 01/25/2016] [Indexed: 11/19/2022]
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de Vries R, van Knegsel A, Johansson M, Lindmark-Månsson H, van Hooijdonk T, Holtenius K, Hettinga K. Effect of shortening or omitting the dry period of Holstein-Friesian cows on casein composition of milk. J Dairy Sci 2015; 98:8678-87. [DOI: 10.3168/jds.2015-9544] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2015] [Accepted: 08/21/2015] [Indexed: 11/19/2022]
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Jensen HB, Pedersen KS, Johansen LB, Poulsen NA, Bakman M, Chatterton DE, Larsen LB. Genetic variation and posttranslational modification of bovine κ-casein: Effects on caseino-macropeptide release during renneting. J Dairy Sci 2015; 98:747-58. [DOI: 10.3168/jds.2014-8678] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 10/17/2014] [Indexed: 11/19/2022]
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Bonfatti V, Chiarot G, Carnier P. Glycosylation of κ-casein: Genetic and nongenetic variation and effects on rennet coagulation properties of milk. J Dairy Sci 2014; 97:1961-9. [DOI: 10.3168/jds.2013-7418] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Accepted: 12/26/2013] [Indexed: 11/19/2022]
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9
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Factors influencing casein micelle size in milk of individual cows: Genetic variants and glycosylation of κ-casein. Int Dairy J 2014. [DOI: 10.1016/j.idairyj.2013.08.001] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Jensen H, Poulsen N, Andersen K, Hammershøj M, Poulsen H, Larsen L. Distinct composition of bovine milk from Jersey and Holstein-Friesian cows with good, poor, or noncoagulation properties as reflected in protein genetic variants and isoforms. J Dairy Sci 2012; 95:6905-17. [DOI: 10.3168/jds.2012-5675] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Accepted: 08/25/2012] [Indexed: 11/19/2022]
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Jensen HB, Holland JW, Poulsen NA, Larsen LB. Milk protein genetic variants and isoforms identified in bovine milk representing extremes in coagulation properties. J Dairy Sci 2012; 95:2891-903. [PMID: 22612926 DOI: 10.3168/jds.2012-5346] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Accepted: 02/02/2012] [Indexed: 11/19/2022]
Abstract
A gel-based proteomic approach consisting of 2-dimensional gel electrophoresis coupled with mass spectrometry was applied for detailed protein characterization of a subset of individual milk samples with extreme rennet coagulation properties. A milk subset with either good or poor coagulation abilities was selected from 892 Danish Holstein-Friesian and Jersey cows. Screening of genetic variants of the major milk proteins resulted in the identification of common genetic variants of β-casein (CN; A(1), A(2), B), κ-CN (A, B), and β-lactoglobulin (LG; A, B), as well as a low frequency variant, κ-CN variant E, and variants not previously reported in Danish breeds (i.e., β-CN variant I and β-LG variant C). Clear differences in the frequencies of the identified genetic variants were evident between breeds and, to some extent, between coagulation groups within breeds, indicating that an underlying genetic variation of the major milk proteins affects the overall milk coagulation ability. In milk with good coagulation ability, a high prevalence of the B variants of all 3 analyzed proteins were identified, whereas poorly coagulating milk was associated with the β-CN variant A(2), κ-CN variant A or E, and β-LG variant A or C. The β-CN variant I was identified in milk with both good and poor coagulation ability, a variant that has not usually been discriminated from β-CN variant A(2) in other studied cow populations. Additionally, a detailed characterization of κ-CN isoforms was conducted. Six κ-CN isoforms varying in phosphorylation and glycosylation levels from each of the genetic variants of κ-CN were separated and identified, along with an unmodified κ-CN form at low abundance. Relative quantification showed that around 95% of total κ-CN was phosphorylated with 1 or 2 phosphates attached, whereas approximately 35% of the identified κ-CN was glycosylated with 1 to 3 tetrasaccharides. Comparing isoforms from individual samples, we found a very consistent κ-CN isoform pattern, with only minor differences in relation to breed, κ-CN genetic variant, and milk coagulation ability.
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Affiliation(s)
- H B Jensen
- Department of Food Science, Aarhus University, 8830 Tjele, Denmark.
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How to tailor heat-induced whey protein/κ-casein complexes as a means to investigate the acid gelation of milk—a review. ACTA ACUST UNITED AC 2011. [DOI: 10.1007/s13594-011-0013-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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13
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Abstract
SUMMARYHeat coagulation time-pH curves at 140°C were obtained for 43 blended skim milk samples from Holstein cows to determine the effects of genetic variants of κ-casein and β-lactoglobulin on milk heat stability. The blended milk samples were similar in terms of protein content and milk salts, but were genotypically different for κ-casein (AA, AB) and β-lactoglobulin (AA, AB, BB). Type A curves were obtained for all milks. Maximum heat stability was affected by the κ-casein genotype (AB > AA, P < 0·01) but the influence of the β-lactoglobulin genotype was only significant when the κ-casein AA genotype was present (β-lactoglobulin AA > BB, P < 0·0001). Minimum heat stability was significantly higher (P < 0·0001) for milk genotyped κ-casein AB:β-lactoglobulin BB. The effects of milk genotyped κ-casein BB on maximum and minimum heat stability were determined by analysing individual milks: κ-casein BB:β-lactoglobulin AB (n=8) and reconstituted milks: κ-casein BB:β-lactoglobulin AA, AB and BB (n = 17). Type B curves were obtained on three occasions for individual κ-casein BB:β-lactoglobulin AB milk and on five occasions in the case of reconstituted milks with κ-casein BB:β-lactoglobulin AA, AB and BB. This suggests a relationship between the type B curve and the κ-casein B genetic variant. Comparison of the mean values of heat stability at the pH of maximum heat stability of each individual and reconstituted milk genotype suggested that the best genotype for κ-casein in terms of heat stability was BB.
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Abstract
SummaryA microparticle-enhanced nephelometric immunoassay has been developed for the determination of caseinomacropeptide (CMP) in bovine milk. It is based on the nephelometric quantification of the competitive immunoagglutination of a microparticle–CMP conjugate with an anti-κ-casein (κ-CN) antiserum. This one step immunoassay was sensitive (detection limit in reaction mixture, 16μg/l), accurate (linear recovery of CMP in dilution overloading) and reproducible (CV 7–14% for within and between run precision). Because of the specificity of the polyclonal antiserum used, it was necessary to separate CMP from κ-CN by ultrafiltration before the quantification of bovine milk CMP. Under the conditions of milk ultrafiltration used, κ-CN was entirely retained (> 99·5%) but the concentration of CMP measured in milk ultrafiltrates was underestimated (by ∼25%) compared with its concentration in whole milk. Microparticle-enhanced nephelometric immunoassay of CMP, with a calibration range from 0·32 to 20 mg/1 for 20- fold diluted milk ultrafiltrate, allowed contamination of bovine milk by rennet whey as low as 5 ml/1 to be detected. Applied to ultrafiltrates from milk stored at 4 °C, this immunoassay also detected proteolysis of κ-CN not revealed by measurement of κ-CN concentration in milk. A statistical lower limit of 3·21 mg/1 was determined as the increase in CMP concentration in milk ultrafiltrates that indicated probable κ-CN proteolysis in the milk sample. Previously demonstrated to be an easy to perform method for assaying the main proteins of bovine milk, microparticle-enhanced nephelometric immunoassay thus also appeared to be appropriate to quantify CMP so as to detect slight contamination of milk by whey and to indicate the proteolysis of κ-CN during milk storage at low temperature.
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Rouch DA, Roginski H, Britz ML, Roupas P. Determination of a nitrogen conversion factor for protein content in Cheddar cheese. Int Dairy J 2008. [DOI: 10.1016/j.idairyj.2007.07.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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16
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Kuy S, Kelly VC, Smit AM, Palmer DJ, Cooper GJ. Proteomic analysis of whey and casein proteins in early milk from the marsupial Trichosurus vulpecula, the common brushtail possum. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2007; 2:112-20. [DOI: 10.1016/j.cbd.2007.01.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2006] [Revised: 01/17/2007] [Accepted: 01/20/2007] [Indexed: 10/23/2022]
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17
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Manso MA, López-Fandiño R. κ-Casein Macropeptides from Cheese Whey: Physicochemical, Biological, Nutritional, and Technological Features for Possible Uses. FOOD REVIEWS INTERNATIONAL 2004. [DOI: 10.1081/fri-200033456] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Moreno FJ, Villamiel M, López-Fandiño R, Olano A. Analysis of monosaccharides in bovine, caprine and ovine κ-casein macropeptide by gas chromatography. Chromatographia 2001. [DOI: 10.1007/bf02491616] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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20
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Determination of the stability of caseinoglycomacropeptide in a cosmetic lotion by use of capillary zone electrophoresis with a coated capillary. Chromatographia 1999. [DOI: 10.1007/bf02490834] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Cherkaoui S, Doumenc N, Tachon P, Neeser JR, Veuthey JL. Development of a capillary zone electrophoresis method for caseinoglycomacropeptide determination. J Chromatogr A 1997; 790:195-205. [PMID: 9435120 DOI: 10.1016/s0021-9673(97)00756-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Caseinoglycomacropeptide (CGMP) is a polypeptide of 64 amino acid residues, derived from the C-terminal part of bovine kappa-casein. A sensitive and selective capillary zone electrophoresis method has been developed and validated for the analysis and quantitation of CGMP. Separation is carried out at 30 kV, using an uncoated fused-silica capillary and 20 mM sodium citrate buffer at acidic pH 3.5. The described method allows the separation of various CGMP subcomponents. The validation data proves that the method has the requisite selectivity, sensitivity, reproducibility and linearity for CGMP assay and for quality control during CGMP manufacturing (batch-to-batch reproducibility).
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Affiliation(s)
- S Cherkaoui
- Laboratory of Pharmaceutical Analytical Chemistry, University of Geneva, Switzerland
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22
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Dziuba J, Minkiewicz P. Influence of glycosylation on micelle-stabilizing ability and biological properties of C-terminal fragments of cow's κ-casein. Int Dairy J 1996. [DOI: 10.1016/0958-6946(95)00074-7] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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23
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Coolbear KP, Elgar DF, Ayers JS. Profiling of genetic variants of bovine κ-casein macropeptide by electrophoretic and chromatographic techniques. Int Dairy J 1996. [DOI: 10.1016/s0958-6946(96)00034-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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24
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Mollé D, Léonil J. Heterogeneity of the bovine kappa-casein caseinomacropeptide, resolved by liquid chromatography on-line with electrospray ionization mass spectrometry. J Chromatogr A 1995; 708:223-30. [PMID: 7647926 DOI: 10.1016/0021-9673(95)00386-2] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Microheterogeneity occurs in the population of caseinomacropeptides (residues 106-169 of kappa-casein) due to variation in the extent and type of oligosaccharide linked to this phosphoglycopeptide. Although caseinomacropeptide A variant (CMPA) was poorly resolved using reversed-phase high-performance liquid chromatography (RP-HPLC) with spectrophotometric detection, it could be analysed with on-line electrospray-ionization mass spectrometry (ESI-MS). From the already established O-linked glycan chains at least fourteen glycosylated forms of CMPA were identified, besides the non-glycosylated and multiphosphorylated (1, 2 or 3 phosphate groups) peptides, giving a maximum number of eighteen known forms. Major subcomponents in CMPA are disialylated species. A maximum of three out of the five potential glycosylation sites were found to be substituted with carbohydrate chains in the most highly glycosylated forms, which may contain up to six N-acetylneuraminic acid residues per molecule. A minor form, diphosphorylated with one disialylated chain, was also detected. From these results, it was shown that the on-line coupling of HPLC with ESI-MS offers a very promising alternative for the analysis of complex mixtures.
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Affiliation(s)
- D Mollé
- Institut National de la Recherche Agronomique, Laboratoire de Recherches de Technologie Laitière, Rennes, France
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25
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ROUDOT-ALGARON F, BARS D, EINHORN J, ADDA J, GRIPON J. Flavor Constituents of Aqueous Fraction Extracted from Comte Cheese by Liquid Carbon Dioxide. J Food Sci 1993. [DOI: 10.1111/j.1365-2621.1993.tb06099.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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26
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Graham ER, McKenzie HA, Murphy WH. The isolation and properties of whole casein: some implications for comparative studies. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. B, COMPARATIVE BIOCHEMISTRY 1993; 104:747-57. [PMID: 8472543 DOI: 10.1016/0305-0491(93)90208-m] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
1. Problems in the isolation of whole casein from bovine milk are considered. A summary is given of our experiences in its isolation. 2. The physical characteristics, sedimentation velocity, heterogeneity, absorptivity, nitrogen, phosphorus and carbohydrate contents of whole casein prepared from normal and sub-clinical mastitic milk samples by a variety of methods are compared. The methods are acid precipitation, high-speed centrifugation, with and without added calcium (II), and ammonium sulphate precipitation. 3. A description is given of the low temperature ammonium sulphate procedure preferred for the isolation of whole casein, especially when it is to be used for subsequent fractionation for conformation and micelle studies. 4. The question of the use of bovine casein as a paradigm for the caseins of other mammalian species and the need for further studies of the physical, chemical and biological properties of the caseins are discussed.
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Affiliation(s)
- E R Graham
- John Curtin School of Medical Research, Australian National University, Canberra
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27
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Robitaille G, Ng-Kwai-Hang KF, Monardes HG. Effect of κ-casein glycosylation on cheese yielding capacity and coagulating properties of milk. Food Res Int 1993. [DOI: 10.1016/0963-9969(93)90079-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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28
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Robitaille G, Ng-Kwai-Hang KF, Monardes HG. Association of kappa-casein glycosylation with milk production and composition in Holsteins. J Dairy Sci 1991; 74:3314-7. [PMID: 1744262 DOI: 10.3168/jds.s0022-0302(91)78518-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A total of 545 milk samples were collected from 53 Holstein cows for 1 yr. On test day, morning milk yields were recorded; milk samples were analyzed for N-acetylneuraminic acid, protein, fat, casein, kappa-casein, and SCC. the relationship between the degree of glycosylation of kappa-casein and morning milk yield and composition was investigated. Data were analyzed using least squares procedures with a model that included test day, parity, stage of lactation, SCC, and phenotype for kappa-casein as fixed effects and N-acetylneuraminic acid content of kappa-casein as covariate. After adjustments were made for effects of environmental and genetic factors, the degree of glycosylation of kappa-casein was associated with morning milk yield, protein, and casein content. Milk yield increased linearly with an increase of N-acetylneuraminic content up to approximately 70 micrograms/mg of kappa-casein.
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Affiliation(s)
- G Robitaille
- Department of Animal Science, Macdonald College, McGill University, Ste. Anne de Bellevue, PQ, Canada
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