Quantification of β-Casein in Milk and Cheese Using an Optical Immunosensor
2004; American Chemical Society; Volume: 52; Issue: 4 Linguagem: Inglês
10.1021/jf034723o
ISSN1520-5118
AutoresStéphanie Muller-Renaud, Didier Dupont, Philippe Dulieu,
Tópico(s)Milk Quality and Mastitis in Dairy Cows
Resumobeta-Casein was quantified in milk and cheese, using an optical immunosensor, based on surface plasmon resonance (SPR) measurement. The assay consists of a two-step sandwich strategy, with two anti-beta-casein antibodies directed against each extremity of the casein. This strategy permits only native beta-casein to be quantified and not its degradation products. The calibration curve was obtained with a reference milk powder of known beta-casein concentration. The analysis time per sample was less than 10 minutes. The antibody-coated surface could be used for more than 250 determinations. The detection limit was established at 85 ng x mL(-)(1) and the intra- and inter-assay variation coefficients were 2.6 and 6.2% respectively. The method was applied to raw milk to quantify intact beta-casein, with no pretreatment of the sample. A second application was realized with cheese, to follow the proteolysis of beta-casein during ripening.
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