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Grewal MK, Vasiljevic T, Huppertz T. Influence of calcium and magnesium on the secondary structure in solutions of individual caseins and binary casein mixtures. Int Dairy J 2021. [DOI: 10.1016/j.idairyj.2020.104879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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de Kruif CGK, Pedersen J, Huppertz T, Anema SG. Coacervates of lactotransferrin and β- or κ-casein: structure determined using SAXS. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:10483-10490. [PMID: 23859400 DOI: 10.1021/la402236f] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Lactotransferrin (LF) is a large globular protein in milk with immune-regulatory and bactericidal properties. At pH 6.5, LF (M = 78 kDa) carries a net (calculated) charge of +21. β-Casein (BCN) and κ-casein (KCN) are part of the casein micelle complex in milk. Both BCN and KCN are amphiphillic proteins with a molar mass of 24 and 19 kDa and carry net charges of -14 and -4, respectively. Both BCN and KCN form soap-like micelles, with 40 and 65 monomers, respectively. The net negative charges are located in the corona of the micelles. On mixing LF with the caseins, coacervates are formed. We analyzed the structure of these coarcervates using SAXS. It was found that LF binds to the corona of the micellar structures, at the charge neutrality point. BCN/LF and KCN/LF ratios at the charge neutrality point were found to be ~1.2 and ~5, respectively. We think that the findings are relevant for the protection mechanism of globular proteins in bodily fluids where unstructured proteins are abundant (saliva). The complexes will prevent docking of enzymes on specific charged groups on the globular protein.
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Affiliation(s)
- C G Kees de Kruif
- Van 't Hoff laboratory for Physical and Colloid Chemistry, Padualaan 8, Utrecht University, The Netherlands.
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4
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Hydrolysis of β-casein by the cell-envelope-located PI-type protease of Lactococcus lactis: A modelling approach. Int Dairy J 2011. [DOI: 10.1016/j.idairyj.2011.03.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Kosters HA, Wierenga PA, de Vries R, Gruppen H. Characteristics and Effects of Specific Peptides on Heat-Induced Aggregation of β-Lactoglobulin. Biomacromolecules 2011; 12:2159-70. [DOI: 10.1021/bm2002285] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Hans A. Kosters
- TI Food and Nutrition, Wageningen, The Netherlands
- NIZO Food Research B.V., Ede, The Netherlands
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6
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Kosters H, Wierenga P, Gruppen H. SELDI-TOF-MS as a rapid tool to study food related protein–peptide interactions. Food Hydrocoll 2010. [DOI: 10.1016/j.foodhyd.2010.03.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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7
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Senocq D, Dupont D, Rolet-Répécaud O, Levieux D. Monoclonal Antibodies against Bovine β-Casein: Production and Epitope Characterization. FOOD AGR IMMUNOL 2010. [DOI: 10.1080/09540100120094483] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022] Open
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8
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Henderson MJ, Perriman AW, Robson-Marsden H, White JW. Protein-poly(silicic) acid interactions at the air/solution interface. J Phys Chem B 2007; 109:20878-86. [PMID: 16853707 DOI: 10.1021/jp051908k] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The structure of the interface generated by a spread layer of beta-casein on an aqueous colloidal poly(silicic) acid subphase is described. The results are compared with data for the protein alone spread at the air/water interface and the silicate solution. Films develop at the air-solution interface and a strong pH dependence of the interaction causing this is demonstrated. Reflectometry with X-rays and neutrons was used to probe the interaction as a function of subphase pH and film compression. Film thickness, tau/A, scattering length density, rho/A(-2), water volume fraction, phi(w), and surface coverage, Gamma/mg m(-2), were used to quantify the interfacial structure. Where possible, the X-ray and neutron data sets were co-refined enabling phi(w) to be evaluated without assumption regarding the protein density. At pH 5-7, strong protein-silicate interaction occurred, the interface comprising three regions: a discrete protein upper layer on top of a 15 +/- 2 A layer of silicated material followed by a diffuse layer that extended into the subphase.
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Affiliation(s)
- Mark J Henderson
- Research School of Chemistry, Australian National University, Canberra 0200, Australia
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Miralles B, Leaver J, Ramos M, Amigo L. Mass mapping analysis as a tool for the identification of genetic variants of bovine beta-casein. J Chromatogr A 2003; 1007:47-53. [PMID: 12924550 DOI: 10.1016/s0021-9673(03)00955-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Matrix-assisted laser desorption ionisation time-of-flight mass spectrometric analysis of the tryptic digest of beta-casein A2 and beta-casein B was performed before and after the separation of the peptides by LC. The overlapping of the chromatograms showed that all peaks were present in both samples, except for one only found in the tryptic digest of the A2 variant and two in the B variant. Experimental masses could be assigned to those peptides produced by tryptic digest of beta-casein variant. This peptide mapping strategy and current methodological improvements represent a promising tool for the identification of milk genetic variants with the difference of an amino acid substitution.
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Affiliation(s)
- B Miralles
- Instituto de Fermentaciones Industriales (CSIC), C/Juan de la Cierva 3, 28006 Madrid, Spain
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11
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Su J, Everett DW. Adsorption of κ-casein onto native milk fat globule, latex particle, and emulsion surfaces. Food Hydrocoll 2003. [DOI: 10.1016/s0268-005x(03)00015-8] [Citation(s) in RCA: 7] [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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12
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Dupont D, Rolet-Repecaud O, Senocq D. A new approach to monitoring proteolysis phenomena using antibodies specifically directed against the enzyme cleavage site on its substrate. Anal Biochem 2003; 317:240-6. [PMID: 12758263 DOI: 10.1016/s0003-2697(03)00115-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Proteolysis is a generic biochemical process that is central in all biological activities. A new strategy for monitoring this biochemical process is proposed here. This approach is based on the production of rabbit polyclonal anti-peptide antibodies directly against the cleavage site on the substrate of the enzyme responsible for proteolysis. So long as the molecule's cleavage site is intact, the antibody will bind to the protein. However, after cleavage of the peptide bond by the protease, the antibody will no longer be able to recognize the substrate. Thus, the development of an ELISA that uses this specific antibody allows hydrolysis of the substrate protein to be monitored. Hydrolysis of beta-casein by plasmin, the main indigenous protease of milk, during the ripening of Swiss-type cheese, has been chosen as a model for this study.
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Affiliation(s)
- Didier Dupont
- INRA, Unité de Recherches en Technologie et Analyses Laitières, B.P. 89 F-39801 Poligny Cedex, France.
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Senocq D, Dupont D, Rolet-Répécaud O, Faurie F, Levieux D. Antipeptide antibodies recognizing plasmin sensitive sites in bovine beta-casein sequence. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2001; 49:1571-1577. [PMID: 11312898 DOI: 10.1021/jf001352s] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
To investigate plasmin activity in cheese, we produced antibodies to bovine beta-casein with controlled specificity, suitable as markers of the integrity of the major bonds involved in its initial breakdown. Sixteen rabbits were immunized with synthetic substitutes for six plasmin-sensitive peptides. Antisera raised to the peptides (f20-39), (f40-56), (f94-113), (f184-202), and (f193-209) recognized beta-casein in ACP-ELISA, Western-blot, and biosensor assays. Casein in vitro hydrolysis by plasmin or chymosin reduced the detection of these determinants in ACP-ELISA, in agreement with the enzymatic sensitivity of bonds included within the binding sites, or in their neighborhood. Antiserum to (f20-39) in particular allowed the specific detection of plasmin cleavage at the bond generating gamma1-CN. Antisera to C-terminus preferentially detected the cleavage by chymosin. Immunoassays using these antibodies would allow in situ monitoring of significant proteolysis events without bias originated in the secondary degradation of the released peptides.
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Affiliation(s)
- D Senocq
- INRA-Station de Recherches en Technologie et Analyses Laitières, B.P. 89, F-39801 Poligny, France
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14
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Everett DW, Olson NF. Dynamic rheology of renneted milk gels containing fat globules stabilized with different surfactants. J Dairy Sci 2000; 83:1203-9. [PMID: 10877384 DOI: 10.3168/jds.s0022-0302(00)74985-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Anhydrous milk fat was emulsified with alpha s1-CN (casein), alpha s2-CN, beta-CN, kappa-CN, alpha-lactalbumin, beta-lactoglobulin, Tween 80, or phosphatidylcholine to produce a 30% fat cream in a 0.1 M imidazole pH 7 buffer. The creams were mixed with skim milk to yield a fat content of 3.4% and the viscoelastic properties of the recombined milks clotted with chymosin were measured. Recombined milk containing globules coated with the more amphipathic and phosphorylated alpha s2-CN and beta-CN clotted faster but gel firmness increased more slowly and weaker gels were formed. Gel firmness increased more rapidly for milks containing globules coated with of alpha s1-CN and kappa-CN that possess more uniformly distributed hydrophobic domains.
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Affiliation(s)
- D W Everett
- Department of Food Science, University of Wisconsin, Madison 53706, USA
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Leaver J, Law AJR, Brechany EY. Covalent Modification of Emulsified beta-Casein Resulting from Lipid Peroxidation. J Colloid Interface Sci 1999; 210:207-214. [PMID: 9924125 DOI: 10.1006/jcis.1998.5944] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Competitive displacement of adsorbed protein from emulsion droplets by the surfactant Tween 20 has been used to determine the influence of the oil phase and aging on the behavior of beta-casein, the displaced protein being analyzed by reverse-phase high performance liquid chromatography HPLC. Unlike soluble beta-casein or the protein displaced from tetradecane droplets where aging had no effect on the appearance of the HPLC profile, the protein displaced from a soya oil emulsion interface was observed to change. As the soya oil emulsion aged, the retention time of the protein decreased. Mass spectrometry of the modified protein showed that the molecular weight increased, indicating that some form of covalent modification was occurring. Gas chromatography-mass spectrometry of steam distillates of the samples showed the presence of a variety of aldehydes in microfluidized soya oil samples that were not present in either the original oil or the tetradecane emulsions. Aldehydes, particularly alpha,beta-unsaturated aldehydes (enals), which are the major components formed in these soya oil emulsions, are known to react with nucleophilic amino acid side chains such as lysine. This is the probable cause of the observed modification of the emulsified protein. These aldehydes, whose concentration increased with storage time, are formed by peroxidation of the unsaturated fatty acyl chains present in the soya oil as a result of the microfluidization process used in the preparation of the emulsions. The tryptic peptide pattern also changed with age due to modification of the primary structure of the protein. Potential consequences of these chemical changes arising as a result of microfluidization are discussed. Copyright 1999 Academic Press.
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Affiliation(s)
- J Leaver
- Hannah Research Institute, Ayr, KA6 5HL, Scotland, United Kingdom
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Niño MRR, Sánchez CC, Patino JM. Interfacial characteristics of β-casein spread films at the air–water interface. Colloids Surf B Biointerfaces 1999. [DOI: 10.1016/s0927-7765(98)00072-1] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Hemar Y, Horne DS. A diffusing wave spectroscopy study of the kinetics of Ostwald ripening in protein-stabilised oil/water emulsions. Colloids Surf B Biointerfaces 1999. [DOI: 10.1016/s0927-7765(98)00079-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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18
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Hemar Y, Horne DS. Electrostatic Interactions in Adsorbed Protein Layers Probed by a Sedimentation Technique. J Colloid Interface Sci 1998; 206:138-145. [PMID: 9761637 DOI: 10.1006/jcis.1998.5711] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A simple centrifugation technique has been used to determine the thicknesses of layers of alphaS1-casein and beta-casein adsorbed onto monodisperse polystyrene latex particles. The influence of electrostatic interactions within the layers on their thickness and stabilizing ability is investigated by varying the ionic strength of the suspension or by including calcium ions, known to bind specifically to the caseins. Copyright 1998 Academic Press.
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Affiliation(s)
- Y Hemar
- Hannah Research Institute, Ayr, Scotland, KA6 5HL, United Kingdom
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Husband FA, Wilde PJ, Mackie AR, Garrood MJ. A Comparison of the Functional and Interfacial Properties of beta-Casein and Dephosphorylated beta-Casein. J Colloid Interface Sci 1997; 195:77-85. [PMID: 9441608 DOI: 10.1006/jcis.1997.5137] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The functional and interfacial properties of beta-casein and dephosphorylated beta-casein (DeP beta-casein) were studied at pH 7.0 in 10 mM phosphate buffer. A decrease in emulsion stability and an increase in foamability was observed. Results from a variety of interfacial techniques including electrophoretic mobility, thin film thickness, surface and interfacial tension, surface rheology, adsorbed layer thickness, and adsorption isotherms of dephosphorylated beta-casein and beta-casein are reported. The results demonstrate that the phosphorylated groups of the N-terminal region of beta-casein are important for stabilizing emulsions. This is either as a direct result of charge repulsion between beta-casein N-terminal regions or more probably as an indirect result of the reduced N-terminal charge permitting DeP beta-casein to adopt a different interfacial conformation resulting in a loss or reduction of a steric barrier. Copyright 1997 Academic Press. Copyright 1997Academic Press
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Affiliation(s)
- FA Husband
- Food Biophysics Department, Institute of Food Research, Norwich Laboratory, Norwich Research Park, Colney Lane, Norwich, NR4 7UA, United Kingdom
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Imafidon GI, Farkye NY, Spanier AM. Isolation, purification, and alteration of some functional groups of major milk proteins: a review. Crit Rev Food Sci Nutr 1997; 37:663-89. [PMID: 9408731 DOI: 10.1080/10408399709527794] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
This review covers selected methods of isolation and purification of mainly alpha s-casein, beta-casein, kappa-casein, beta-lactoglobulin, and alpha-lactalbumin. Selected methods of alteration of some functional groups of these proteins also were reviewed. Isolation and purification of milk proteins per se are methods of modifying the individual milk proteins. Gram quantities of these proteins can now be purified in a relatively short time using ion-exchange resins. Due to the prominent use of non-food-grade reagents in the procedures for preparation of these milk proteins, individual proteins are not maximally utilized for the manufacture of food/feed and pharmaceutical products. Therefore, intensive research efforts are needed to obviate the problems associated with underutilization of milk proteins.
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Stevenson EM, Horne DS, Leaver J. Displacement of native and thiolated β-casein from oil—water interfaces—effect of heating, ageing and oil phase. Food Hydrocoll 1997. [DOI: 10.1016/s0268-005x(97)80003-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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22
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Wong CW, Seow HF, Liu AH, Husband AJ, Smithers GW, Watson DL. Modulation of immune responses by bovine beta-casein. Immunol Cell Biol 1996; 74:323-9. [PMID: 8872182 DOI: 10.1038/icb.1996.58] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The present reports the influence of bovine beta-casein on in vitro and in vivo immune responses. Bovine beta-casein showed an inhibitory effect on ovine neutrophil chemotaxis but had an enhancing effect on superoxide production by neutrophils. In response to mitogenic stimulation, the proliferative response of both T and B lymphocytes was significantly enhanced by beta-casein. While beta-casein had no significant effects on IFN gamma production by ovine blood lymphocytes, and TNF alpha production and MCH Class II antigen expression by ovine bronchoalveolar macrophages, it enhanced IL-1 beta production by the macrophages, beta-casein also had no influence on bovine NK cell activity against a virally-infected cell line. Interestingly, beta-casein was found to reduce the adjuvant effect of matrix immune stimulating complexes (ISCOM) on anti-ovalbumin antibody response in mice when given intramuscularly. Taken together, the results suggest that bovine beta-casein had selective modulating effects in vitro on both innate and adaptive immune responses in ruminants, whereas systemic administration of beta-casein, that might have a depressive effect on adjuvant activity, requires further study.
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Affiliation(s)
- C W Wong
- CSIRO Division of Animal Health, Armidale, New South Wales, Australia
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24
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Everett DW, Ding K, Olson NF, Gunasekaran S. Applications of confocal microscopy to fat globule structure in cheese. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1995; 367:321-30. [PMID: 7572372 DOI: 10.1007/978-1-4615-1913-3_20] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- D W Everett
- Department of Food Science, University of Wisconsin, Madison 53706, USA
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Brooksbank DV, Davidson CM, Horne DS, Leaver J. Influence of electrostatic interactions on β-casein layers adsorbed on polystyrene latices. ACTA ACUST UNITED AC 1993. [DOI: 10.1039/ft9938903419] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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