Variance of Commercial Powdered Milks Analyzed by 1H-NMR and Impact on Detection of Adulterants.
Related Articles Variance of Commercial Powdered Milks Analyzed by 1H-NMR and Impact on Detection of Adulterants.
J Agric Food Chem. 2018 Apr 26;:
Authors: Harnly JM, Bergana MM, Adams KM, Moore JC, Xie Z
Abstract
1H-NMR spectra for 66 commercial powdered milk samples were analyzed by PCA, SIMCA, and pooled, crossed ANOVA. It was found that the sample type (skim milk powder or non-fat dry milk), the supplier, the production site, the processing temperature (high, medium, or low temperature), and the day of analysis provided statistically significant sources of variation. Interestingly, inexact alignment (deviations of ±0.002 ppm) of the spectral reference peak was a significant source of variation and fine alignment was necessary before the variation arising from the other experimental factors could be accurately evaluated. Using non-targeted analysis, the lowest detectable adulteration for dicyandiamide, melamine, and sucrose was 0.05%, maltodextrin and urea was 0.5%, ammonium sulfate and whey was 5%, and soy protein isolate was undetectable using methods described herein. The measurement of variance and detection of adulteration were relatively unaffected by the resolution. Similar results were obtained with un-binned data (0.0003 ppm resolution) and binning of 333 data points (0.1 ppm resolution).
PMID: 29697263 [PubMed - as supplied by publisher]
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