Bovine caseins in dairy and dairy products were determined by high performance liquid chromatography (HPLC) with a PDA detector at 280 nm or by sandwich ELISA method. Liquid chromatography method was developed to determine different types of casein including alpha, beta, and kappa casein at high content (% level), which calculate the proportion of casein forms, thus allow the identification of milk sources (cow's milk, goat's milk). The ELISA method determines casein at low content (LOD was of 3mg/kg) which meets the labeling requirements of EU and Japan for food allergens. The validation data show that both methods fit the purpose with the recovery of 78-98% and the coefficient of variation is from 2.4 to 9.5%. The methods have been applied for the determination of casein content in 20 samples of milk, food supplement, cake and candy from Hanois' markets.
HPLC, ELISA, casein, milk
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