Milk protein adulteration detection via mass spectra and infrared spectroscopy
type: CreativeWork
description: Milk protein adulteration concerns the addition of cheap foreign substance having high nitrogen content into milk and dairy products, to mask low natural protein in milk. Plant protein is a potential candidate of adulterants; soy, pea, wheat, and rice proteins being the most popular. The consumption of those adulterants could induce serious Human health disorders. Therefore, the development of detection methods for protein milk adulteration is of great importance to guarantee food safety. The current thesis aims to test and compare methods such as two-dimensional gel electrophoresis (2-DE), liquid chromatography tandem mass spectrometry, and infrared spectroscopy to detect foreign protein spiked in milk, especially hydrolyzed plant proteins. Here are the major results: (1) According to the protein spots highlighted on the polyacrylamide gel of adulterated milk, β-conglycinin and glycinin were detected in milk adulterated with soy protein, while legumin, vicilin, and convicilin indicated the addition of pea protein, and β-amylase and serpin marked wheat protein. 2-DE-based protein profile allowed to identify milk spiked with soy and pea protein, with a detection limit of 4% plant protein in the total protein. (2) Sodium dodecyl sulfate -polyacrylamide gel electrophoresis (SDS-PAGE) gels revealed clearly that centrifugation at 20 000 g for 60 min reduced band intensity of casein and albumin in milk. No obvious protein line was observed for hydrolyzed wheat and rice protein. Results of nano-HPLC-MS/MS highlighted the major proteins of soy (β-conglycinin, glycinin), pea (vincilin, convicilin, legumin) and wheat (glutenin and gliadin) in adulterated milks. So, this method allows the detection of hydrolyzed soy and wheat protein at the level above 0.5% in total protein, and pea protein at the level of 2 and 4%. No rice protein was identified in milk samples adulterated with hydrolyzed rice protein. Combined with principal component analysis (PCA), nano-HPLC-MS/MS discrimi…
abstract: Milk protein adulteration concerns the addition of cheap foreign substance having high nitrogen content into milk and dairy products, to mask low natural protein in milk. Plant protein is a potential candidate of adulterants; soy, pea, wheat, and rice proteins being the most popular. The consumption of those adulterants could induce serious Human health disorders. Therefore, the development of detection methods for protein milk adulteration is of great importance to guarantee food safety. The current thesis aims to test and compare methods such as two-dimensional gel electrophoresis (2-DE), liquid chromatography tandem mass spectrometry, and infrared spectroscopy to detect foreign protein spiked in milk, especially hydrolyzed plant proteins. Here are the major results: (1) According to the protein spots highlighted on the polyacrylamide gel of adulterated milk, β-conglycinin and glycinin were detected in milk adulterated with soy protein, while legumin, vicilin, and convicilin indicated the addition of pea protein, and β-amylase and serpin marked wheat protein. 2-DE-based protein profile allowed to identify milk spiked with soy and pea protein, with a detection limit of 4% plant protein in the total protein. (2) Sodium dodecyl sulfate -polyacrylamide gel electrophoresis (SDS-PAGE) gels revealed clearly that centrifugation at 20 000 g for 60 min reduced band intensity of casein and albumin in milk. No obvious protein line was observed for hydrolyzed wheat and rice protein. Results of nano-HPLC-MS/MS highlighted the major proteins of soy (β-conglycinin, glycinin), pea (vincilin, convicilin, legumin) and wheat (glutenin and gliadin) in adulterated milks. So, this method allows the detection of hydrolyzed soy and wheat protein at the level above 0.5% in total protein, and pea protein at the level of 2 and 4%. No rice protein was identified in milk samples adulterated with hydrolyzed rice protein. Combined with principal component analysis (PCA), nano-HPLC-MS/MS discrimi…
author: Yang, Jinhui
language: en
keywords: milk protein adulteration, two-dimensional electrophoresis, high performance liquid chromatography tandem mass spectrum, near- and mid- infrared spectroscopy, Life sciences, Agriculture & agronomy, Sciences du vivant, Agriculture & agronomie
license: http://purl.org/coar/access_right/c_abf2
date published: 2019-01-21
date modified: 2026-07-24T02:49:37Z
provider: Université de Liège
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: ULiège - Université de Liège