Validation of method for the determination of bovine casein in milk and milk products

Abstract

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.