title: Quantification of bovine β-casein allergen in baked foodstuffs based on ultra-performance liquid chromatography with tandem mass spectrometry.
abstract: The quantification of allergens in food including baked food matrices is of great interest. The aim of the present study was to describe a non-immunologic method to quantify bovine β-casein using ultra-performance liquid chromatography tandem triple quadrupole mass spectrometry (UPLC-TQ-MS/MS) in multiple reaction monitoring (MRM) mode. Eight of 10 theoretical peptides from β-casein after tryptic digestion were compared and MRM methods were developed to determine five signature peptides. The peptide VLPVPQK was selected as the signature peptide for bovine β-casein because of the high sensitivity. A stable isotope-labelled internal standard was designed to adjust the instability of sample pre-treatment and ionisation caused by matrix effect. Using the present suspension digestion method, the native and denatured β-casein could be digested to release the signature peptide at the maximum extent. The UPLC-TQ-MS/MS method developed based on a tryptic signature peptide led to a reliable determination of bovine β-casein allergen in baked food matrices at a low quantitation level down to 500 μg kg(-1) with a satisfactory accuracy (< 8.9%) and recovery (98.8% ± 2.6% to 106.7% ± 3.0%).
authors.affiliation: a Zhejiang Provincial Center for Disease Control and Prevention , Hangzhou , China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Chen
authors.forename: Jingshun
authors.initials: J
authors.lastname: Zhang
authors.forename: Xing
authors.initials: X
authors.lastname: Ke
authors.forename: Shiyun
authors.initials: S
authors.lastname: Lai
authors.forename: Baohua
authors.initials: B
authors.lastname: Tao
authors.forename: Jinchuan
authors.initials: J
authors.lastname: Yang
authors.forename: Weimin
authors.initials: W
authors.lastname: Mo
authors.forename: Yiping
authors.initials: Y
authors.lastname: Ren
mesh_terms: D000485:Allergens / Q000032:analysis* / Q000737:chemistry; D000595:Amino Acid Sequence; D000818:Animals; D001939:Bread / Q000032:analysis*; D002364:Caseins / Q000032:analysis* / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D005512:Food Hypersensitivity / Q000503:physiopathology; D006801:Humans; D007553:Isotope Labeling; D008894:Milk Proteins / Q000032:analysis* / Q000737:chemistry; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000302:isolation & purification*; D059748:Proteolysis; D053719:Tandem Mass Spectrometry; D014357:Trypsin / Q000737:chemistry
chemical_list: D000485:Allergens; D002364:Caseins; D008894:Milk Proteins; D010446:Peptide Fragments; D014357:Trypsin
keywords: allergens; baked foodstuffs; bovine β-casein; isotope-labelled peptide; suspension digestion; tryptic digestion