title: Quantification of dabsylated di- and tri-peptides in fermented milk.
abstract: An improved HPLC method using pre-column dabsyl chloride derivatisation for the separation and quantification of antihypertensive di- and tri-peptides in fermented milk products was established. The dabsylated peptides Val-Pro-Pro (VPP), Ile-Pro-Pro (IPP), Leu-Pro-Pro (LPP) and Phe-Pro (FP) were separated on a C18-column coupled to UV/VIS and mass spectrometric detector, respectively. Due to the derivatisation of the peptides, an HPLC base line separation was achieved and the peak width was improved. The VIS-spectrometry did not allow a good quantification of these peptides since more than one peptide co-eluted under one single peak. In contrast applying LC-ESI-MS with a single quadrupole much better quantification of the dabsylated peptides was done. In Evolus® (Valio Ltd., Finland), a fermented milk drink, 6.9 mg L(-1) for VPP, 6.1 mg L(-1) for IPP, 0.8 mg L(-1) for LPP and 3.2 mg L(-1) for FP were determined. In fermented reconstituted milk (Lactobacillus helveticus, 37°C, 48 h) lower concentrations of these peptides were determined (0.7, 0.6, 0.0 and 2.2 mg L(-1), respectively).
authors.affiliation: Department of Biotechnology, Institute of Food Science and Biotechnology, University of Hohenheim, Garbenstr. 25, 70599 Stuttgart, Germany. t.eisele@uni-hohenheim.de
authors.forename: T
authors.initials: T
authors.lastname: Eisele
authors.forename: T
authors.initials: T
authors.lastname: Stressler
authors.forename: B
authors.initials: B
authors.lastname: Kranz
authors.forename: L
authors.initials: L
authors.lastname: Fischer
mesh_terms: D000818:Animals; D002853:Chromatography, Liquid / Q000379:methods*; D043302:Cultured Milk Products / Q000737:chemistry* / Q000382:microbiology; D005285:Fermentation; D007536:Isomerism; D052198:Lactobacillus helveticus / Q000378:metabolism; D009842:Oligopeptides / Q000737:chemistry* / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D009842:Oligopeptides