Milk-based infant formula powders � Quantification of whey protein content by sodium dodecyl sulfate-capillary gel electrophoresis (SDS-CGE)

2020 ◽  
Keyword(s):  
Sodium Dodecyl Sulfate ◽  
Protein Content ◽  
Whey Protein ◽  
Infant Formula ◽  
Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Capillary Gel Electrophoresis ◽  
Dodecyl Sulfate

Quantification of Whey Protein Content in Milk-Based Infant Formula Powders by Sodium Dodecyl Sulfate–Capillary Gel Electrophoresis (SDS-CGE): Multilaboratory Testing Study, Final Action 2016.15

2018 ◽  
Vol 101 (5) ◽  
pp. 1566-1577 ◽  
Author(s):  
Ping Feng ◽  
Christophe Fuerer ◽  
Adrienne McMahon ◽  
K Arendse ◽  
A Chanady ◽  
...  
Keyword(s):  
Sodium Dodecyl Sulfate ◽  
Young Children ◽  
Protein Content ◽  
Whey Protein ◽  
Infant Formula ◽  
Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Capillary Gel Electrophoresis ◽  
Dodecyl Sulfate ◽  
Infants And Young Children

Abstract A multilaboratory testing study was conducted on AOAC First Action Official Method SM 2016.15: Quantification of Whey Protein Content in Infant Formula Powders by Sodium Dodecyl Sulfate–Capillary Gel Electrophoresis (SDS-CGE). Nineteen laboratories participated in the analysis of duplicate blind-coded samples of 15 formula powder products for infants and young children. Electrophoregrams were recorded at UV220 nm and integrated. The normalized peak areas of whey and casein proteins were summed separately to calculate total whey protein content. Apart from one sample [NIST Standard Reference Material (SRM) 1849a], relative standard deviation of repeatability (RSDr) and reproducibility (RSDR) ranged from 0.83 to 2.11% and from 2.18 to 4.22%, respectively, and Horwitz ratios ranged from 1.02 to 1.85, meeting the precision limits specified in the whey protein Standard Method Performance Requirements and in the guidelines recommended for the Horwitz ratio. In these samples, the measured whey protein content was between 98 and 108% of the declared value. NIST SRM 1849a showed atypical results, with elevated RSDr (3.51%), RSDR (5.94%), Horwitz ratio (2.62), and recovery (134%). There is no clear reason for this. The percent whey protein value for NIST is calculated from the formulation and is not a reference or certified value. Multiple instrument models and makes, as well as capillary sources, were used in this collaborative study, demonstrating the robustness of the method. The method is fit-for-purpose for the quantification of whey protein content in milk-based formula powder products for infants and young children. It is not applicable to the analysis of hydrolyzed or plant protein–based infant formulas.

Quantification of Whey Protein Content in Infant Formulas by Sodium Dodecyl Sulfate-Capillary Gel Electrophoresis (SDS-CGE): Single-Laboratory Validation, First Action 2016.15

2017 ◽  
Vol 100 (2) ◽  
pp. 510-521 ◽  
Author(s):  
Ping Feng ◽  
Christophe Fuerer ◽  
Adrienne McMahon
Keyword(s):  
Sodium Dodecyl Sulfate ◽  
Protein Content ◽  
Whey Protein ◽  
Gel Electrophoresis ◽  
Whey Proteins ◽  
Sodium Dodecyl ◽  
Infant Formulas ◽  
Method Performance ◽  
Capillary Gel Electrophoresis ◽  
Dodecyl Sulfate

Abstract Protein separation by sodium dodecyl sulfate-capillary gel electrophoresis, followed by UV absorption at 220 nm, allows for the quantification of major proteins in raw milk. In processed dairy samples such as skim milk powder (SMP) and infant formulas, signals from individual proteins are less resolved, but caseins still migrate as one family between two groups of whey proteins. In the first group, α-lactalbumin and β-lactoglobulin migrate as two distinct peaks. Lactosylated adducts show delayed migration times and interfere with peak separation, but both native and modified forms as well as other low-MW whey proteins still elute before the caseins. The second group contains high-MW whey proteins (including bovine serum albumin, lactoferrin, and immunoglobulins) and elutes after the caseins. Caseins and whey proteins can thus be considered two distinct nonoverlapping families whose ratio can be established based on integrated areas without the need for a calibration curve. Because mass-to-area response factors for whey proteins and caseins are different, an area correction factor was determined from experimental measurement using SMP. Method performance assessed on five infant formulas showed RSDs of 0.2–1.2% (within day) and 0.5–1.1% (multiple days), with average recoveries between 97.4 and 106.4% of added whey protein. Forty-three different infant formulas and milk powders were analyzed. Of the 41 samples with manufacturer claims, the measured whey protein content was in close agreement with declared values, falling within 5% of the declared value in 76% of samples and within 10% in 95% of samples.

Sodium dodecyl sulfate-capillary gel electrophoresis of polyethylene glycolylated interferon alpha

2004 ◽  
Vol 25 (3) ◽  
pp. 476-479 ◽  
Author(s):  
Dong H. Na ◽  
Eun J. Park ◽  
Yu S. Youn ◽  
Byung W. Moon ◽  
Yeong W. Jo ◽  
...  
Keyword(s):  
Sodium Dodecyl Sulfate ◽  
Interferon Alpha ◽  
Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Capillary Gel Electrophoresis ◽  
Dodecyl Sulfate

Characterization of the H- and L-Subunit Ratios of Ferritins by Sodium Dodecyl Sulfate–Capillary Gel Electrophoresis

2002 ◽  
Vol 302 (2) ◽  
pp. 263-268 ◽  
Author(s):  
John K. Grady ◽  
Jia Zang ◽  
Thomas M. Laue ◽  
Paolo Arosio ◽  
N.Dennis Chasteen
Keyword(s):  
Sodium Dodecyl Sulfate ◽  
Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Capillary Gel Electrophoresis ◽  
Dodecyl Sulfate
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