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Alkaline phosphatase in cow milk

Alkaline phosphatase in cow milk

Alkaline phosphatase (ALP) is an enzyme normally present in raw milk and it is inactivated when thermal treatment conditions are slightly higher than those required for the destruction of the pathogenic bacteria. Hence, the chemical test carried out to determine alkaline phosphatase (ALP) concentration in pasteurized milk is used to verify if thermal treatment has been done correctly.

Instrument

FoodLab

Reagents

R1(pre-filled into the test tube):
    Diethanolammine - 1.0 mol/L pH 10.3
    Magnesium chloride - 0.5 mmol/L
R2 (in bottle):
    p-Nitrophenylphosphate - 10    mmol/L

Test method

Test type End Point
Colour reading at 405 nm
Test time: 30 minutes
It is possible to carry out several test sessions with a maximum of 14 samples.
Calibration can be performed by aligning the test to reference values.

Test principle

The alkaline phosphatase causes the hydrolysis of the Nitrophenylphosphate in a half alkaline and forms a yellow complex whose intensity, measured at 405 nm, is directly proportional to the concentration of ALP in the sample. CDR innovative method simplifies and speeds up the standard procedure.

Sample

Pasteurized cow milk.

Kit

The reagents are provided in sealed bags, each containing 10 test tubes. They have a 12 months duration, starting from the production date. Stocking requirements are described on the bag label.
Reagents do not contain dangerous solvents and are ready for use.