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March 14, 2017
•
Wyeth/Nestle has developed a whey protein analysis method using SDS-CGE
responding to the need of the Chinese regulation of GB 10765-2010 for “milk
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•
The method is innovative (no similar method for infant formulas published or used
before); a single lab validation by Wyeth/Nestle and
an MLT with 4 qualified
Chinese government labs have been finished, and the results are promising.
•
A linearity test by Wyeth/Nestle, 3 levels spike-recovery tests with 4 labs, and
precision test with repeatability, intermediate precision and reproducibility by 4
labs were done following combined GB guidelines and AOAC requirements.
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.
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Although an officer has commented that fit for purpose methods proposed by
reputable manufacturers should be considered, the method still needs to be
submitted via a Chinese government lab.
Whey protein analysis method using SDS-CGE
8
March 14, 2017
Summary of Method Validation Results for
Whey Protein Analysis Using SDS-CGE(1)
Parameter
Acceptance criteria (SPIFAN/SMPR)
Results
Accuracy
The % recovery must lie within the range 95% -
105% of theoretical
% Recovery Range
97.6% - 102.2% in 3 levels and in
4 labs
Precision
–
Repeatability
%RSD 3.0% for whey protein g/100 g protein 0.2% – 2.1% RSD in 4 labs for 4
different infant formula samples
Precision-
Intermediate
Precision
%RSD 3.0% for whey protein g/100 g protein 0.3% - 2.2% RSD in 4 labs for 4
different infant formula samples
Precision
–
Reproducibility
%RSD 6.0% for whey protein g/100 g protein 0.9% - 3.8% RSD in 4 different
labs for 21 different infant formula
samples