Untargeted LC-Q-TOF mass spectrometry method for the detection of adulterations in skimmed-milk powder

• Published in: Journal of separation science 2009-04, Vol.32 (8), p.1216-1223
• Main Authors: Cordewener, Jan H. G., Luykx, Dion M. A. M., Frankhuizen, Rob, Bremer, Maria G. E. G., Hooijerink, Hendricus, America, Antoine H. P.
• Format: Article
• Language: English
• Subjects: Adulteration; Animals; Chromatography, Liquid - instrumentation; Chromatography, Liquid - methods; Comparative LC-MS; dairy-products; Food Analysis - instrumentation; Food Analysis - methods; Food Contamination - analysis; food proteins; Glycine max - chemistry; identification; Mass Spectrometry - instrumentation; Mass Spectrometry - methods; Milk - chemistry; Milk powder; Molecular Sequence Data; Peptides - analysis; Peptides - genetics; Pisum sativum - chemistry; Plant proteins; Plant Proteins - analysis; Plant Proteins - genetics; Powders - chemistry; Q-TOF; quantitative proteomic analysis
• ISSN: 1615-9306; 1615-9314
• DOI: 10.1002/jssc.200800568

A nontargeted protein identification method was developed to screen for adulterations in skimmed‐milk powder (SMP). There are indications of falsified SMP content due to the addition of plant proteins. To demonstrate the reliability and accuracy of the developed comparative LC‐MS method using a quadrupole TOF MS instrument, adulterated SMP samples were prepared by the addition of protein isolates of soy and pea to skimmed‐milk before pasteurisation and evaporation. The comparative LC‐MS approach enabled unequivocal discrimination of those SMP samples containing soy and pea protein from nonadulterated SMP. To identify the source of (plant) proteins present in the adulterated SMP, data‐dependent LC‐MS/MS was used in combination with an include list of differential peptides. Numerous peptides originating from the major seed proteins of soy (glycinin, β‐conglycin) and pea (legumin, vicilin) could be identified in this way.