The Determination Method Of Caseins In Bovine Milk

In the field of food quality, bovine milk products are of particular interest due to the social and economic importance of the dairy products market. However, the risk of fraudulent manipulation is high in this area. Therefore, there is a need to have suitable analytical methods available for the determination of all milk components, which is currently not the case, especially for the caseins.A method for detecting and quantifying caseins in bovine milk by means of enzyme-linked immunosorbent assays (ELISA) is described. The polyclonal antibodies were prepared by immunizing New Zealand rabbits with bovineα_s- casein andκ-casein. The antibodies were tested by ELISA, and the titles ofα_s- casein andκ-casein were 1:1600 and 1:3200 respectively. Quantification was based on calibration curves drawn using purified caseins. The calibration curve ofα_s- casein was linear between 25 and 1200ng/ml with regression coefficients 0.9825, and the recovery rates were between 91.97%~115.61%. The calibration curve ofκ- casein was linear between 25 and 1400ng/ml with regression coefficients 0.9831, and the recovery rates were between 95.83%~125.83%.The ELISA performance makes it suitable for development as a kit, for use in the field as a high throughput screening ELISA. Therefore, the method was successfully applied for authenticity evaluation and quantitative determination of caseins percentages in bovine milk.