Differential milk proteins

Numerous methods have been developed and employed in the fractionation of milk proteins some of these are based on differential solubili-... 

Heid, H.W., Schnolzer, M., Keenan, T.W. 1996. Adipocyte differentiation-related protein is secreted into milk as a constituent of milk lipid globule membrane. Biochem. J. 320, 1025-1030. 

Because the symptoms of lactose intolerance are nonspecific, lactose intolerance needs to be differentiated from other common disorders causing diarrhea and abdominal pain or discomfort. These differential diagnoses include milk protein allergy, gastroenteritis, colitis, and irritable bowel syndrome. Allergy or sensitivity to one or more of cow s milk proteins characteristically occurs in formula-fed infants, and although no age is exempt, it is rare in the older... 

Keenan, Adipocyte differentiation-related protein is secreted into milk as a constituent of milk lipid globule membrane,... 

Both the protein and fat components in milk influence the properties of food, but the ability of the milk to impart desirable properties to food is mostly influenced by the physical functional properties of the milk protein components (Kinsella, 1984 Mulvihill and Fox, 1989). The inherent functionality of milk proteins is related to the structural/ conformational properties of protein, which is influenced by both the intrinsic properties of the protein and extrinsic factors. Modification of the protein composition or structure and the organization of the proteins within the dairy ingredient through the application of physical, chemical, or enzymatic processes, alone or in combination, enable the differentiation of the functionality of the ingredient and designing the required functionality for specific applications (Chobert, 2003 Foegeding et al., 2002). 

A rapid FTIR method for the direct determination of the casein/whey ratio in milk has also been developed [26]. This method is unique because it does not require any physical separation of the casein and whey fractions, but rather makes use of the information contained in the whole spectrum to differentiate between these proteins. Proteins exhibit three characteristic absorption bands in the mid-infrared spectrum, designated as the amide I (1695-1600 cm-i), amide II (1560-1520 cm-i) and amide III (1300-1230 cm >) bands, and the positions of these bands are sensitive to protein secondary structure. From a structural viewpoint, caseins and whey proteins differ substantially, as the whey proteins are globular proteins whereas the caseins have little secondary structure. These structural differences make it possible to differentiate these proteins by FTIR spectroscopy. In addition to their different conformations, other differences between caseins and whey proteins, such as their differences in amino acid compositions and the presence of phosphate ester linkages in caseins but not whey proteins, are also reflected in their FTIR spectra. These spectroscopic differences are illustrated in Figure 15, which shows the so-called fingerprint region in the FTIR spectra of sodium caseinate and whey protein concentrate. Thus, FTIR spectroscopy can provide a means for quantitative determination of casein and whey proteins in the presence of each other. 

Tompa, G., Laine, A., Pihlanto, A., Korhonen, H. J. T., Rogelj, I., Mamila, P. (2011). Chemiluminescence of non-differentiated THP-1 promonocytes developing an assay for screening anti-inflammatory milk proteins and peptides. Luminescence, 26, 251-258. 

The accuracy of SCC determination in composite cow s milk by NIR spectroscopy has allowed health screening of cows and differentiation between healthy and mastitic milk samples. It has been found that SCC determination by NIR milk spectra is based on the related changes in milk composition. The most significant factors that influence NIR spectra of milk are the alteration of milk proteins and changes in ionic concentration of mastitic milk. 

Whether SI consumption leads to differential effects in EQU producers and nonproducers is less clear in relation to cancer risk. There was no difference in mammographic density following a 1-y SP intervention in PMW compared to a milk protein control and this was unaffected by EQU status (Verheus et al. 2008). However, changes in gene expression, some of which were involved in pathways that are related to cell differentiation, increased cAMP signaling and G-protein-coupled protein metabolism, and increased steroid hormone receptor activity, were more marked in the lymphocytes of EQU producers compared to EQU nonproducers (Niculescu et al. 2007). 

Efficiency of endogenous urea nitrogen incorporation into the ruminal bacteria and milk protein in goats fed diet differentiated in protein level... 

Many proteins and polymers have been analyzed on SynChropak GPC and CATSEC columns. Table 10.6 lists some of the published applications. The use of a surfactant to analyze the caseins in milk is illustrated in Eig. 10.12. Viruses have also been analyzed on SynChropak GPC columns, as seen in the chromatogram from Dr. Jerson Silva of the University of Illinois (Pig. 10.13). Dr. Nagy and Mr. Terwilliger analyzed cationic polymers on a series of CATSEC columns using differential viscometry as detection (Pig. 10.14) (9). 

DDBJ—see EMBL DLS—dynamic light scattering DM—donkey s milk DNA—deoxyribonucleic acid DNCB—2,4-dinitrochlorobenzene DSC—differential scanning calorimetry DTH—delayed cellular hypersensitivity DXMS—deuterium exchange mass spectrometry EAACI—European Academy of Allergology and Clinical Immunology EAR—early anaphylactic phase ECFA—eosinophil chemotactic factors of anaphylaxis ECP—eosinophil cationic protein EDN—eosinophil-derived neurotoxin eHF—extensively hydrolyzed formula ELISA—enzyme-linked immunosorbent assay... 

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