Peroxidase test in milk
CDR’s innovative method enables to easily and quickly quantify lactoperoxidase in milk. The test can be carried out on microscopic samples as is and requires the use of a pre-filled reagent in disposable cuvettes.
The persistence of lacto-peroxidase activity in pasteurized milk provides a good indication of the quality of a product, because only a raw milk of good microbiological quality can be put through a mild pasteurization process in order to not inactivate this enzyme. Traditional methods are often qualitative (present/not present) and thus able only to indicate whether the thermal process has been performed. Quantifying lactoperoxidase in pasteurized milk enables instead to determine the nutritional quality of milk. Higher value of peroxidase means that the milk has preserved its original characteristics.
Analyzers for determining Lactose in milk and dairy products
 CDR FOODLAB® |
 CDR FOODLAB® JUNIOR |
|
|---|---|---|
| Analyses | Milk and Dairy Products: Lactose L-Lactic acid Milk Urea Nitrogen (MUN) Alkaline phosphatase (ALP) Ammonia Chloride Hydrogen peroxide ε-fructosyl-lisine (Furosine) Free Fatty Acids Peroxide Value Peroxidase |
Configuration with tailored panel of analyses |
| Simultaneous Sample Analyses | 16 | 3 |
| Multiple Analyses on a Sample |  |
– |
It is not necessary skilled staff nor a laboratory for the analysis.
Results are correlated with reference method results.
It is free of service and maintenance cost.
With the same analyzers you can also perform analysis of egg, tomato, vegetable purees, cheeses and fats.
Method
Test type: End Point
Testing time: one test 10 minutes
Are possible test sessions with several samples, up to a maximum of 16.
The system is supplied pre-calibrated and ready for use.
Principle of the test
H2O2 + indicator 
red coloured indicator
In presence of an indicator and hydrogen peroxide, milk peroxidase catalyzes forming a red compound with an intensity that is directly proportional to the concentration of peroxidase in the sample when measured at 505 nm.
Calibration curve
The quantitative determination of peroxidase is an innovative test and it is therefore not easy to find samples that can be used as reference or official reference methods. Thus, CDR’s laboratories carried out several test, using CDR FoodLab®’s method, on samples of different manufacturers and compared the resulting values with those specified in the technical data sheet of the Reflectoquant® reflectometric method. The results compared well.
Reagent test Kits
The reagents are packaged in foil pouches containing 10 tubes useful to perform 10 analyses.
This is the minimum package that allows the use of CDR systems even to those who need to make a few analyses, thus not wasting reagents.
There are also boxes of 100 tests, however, packaged in 10 bags of 10 tubes containing the reagent.
Code *300525: suitable for 100 tests
Code *300528: suitable for 20 tests
The reagents have a shelf-life of 12 months.
Processing – Sample volume – Measuring range
Use milk as is
| Measuring range | Resolution | Repeatability | |
|---|---|---|---|
| Peroxidase (POD) | 100 – 8000 U/L | 1 U/L | 100 U/L |
| Seroprotein* | 13.60 – 17.70% | 0.01% | 0,1% |
* Indirect determination
