Muller-Renaud Stéphanie, Dupont Didier, Dulieu Philippe
INRA, Unité de Recherches en Technologie et Analyses Laitières, Place du Champ de Foire, F-39800 Poligny, France.
J Agric Food Chem. 2004 Feb 25;52(4):659-64. doi: 10.1021/jf034723o.
beta-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.
使用基于表面等离子体共振（SPR）测量的光学免疫传感器对牛奶和奶酪中的β-酪蛋白进行定量。该测定采用两步夹心策略，使用两种抗β-酪蛋白抗体分别针对酪蛋白的两端。这种策略仅允许对天然β-酪蛋白进行定量，而不能对其降解产物进行定量。使用已知β-酪蛋白浓度的参考奶粉获得校准曲线。每个样品的分析时间少于10分钟。抗体包被的表面可用于超过250次测定。检测限确定为85 ng x mL⁻¹，批内和批间变异系数分别为2.6%和6.2%。该方法应用于原料奶，无需对样品进行预处理即可定量完整的β-酪蛋白。第二个应用是在奶酪上实现的，用于跟踪成熟过程中β-酪蛋白的蛋白水解情况。
