L-Lactic acid in milk

The chemical analysis of the milk and dairy products  for quality control in every stage of the production chain with CDR FoodLabLactic acid is produced by the fermentation of lactose mainly through microbial activity. Its concentration depends on the total bacterial count and can be a useful indicator of the good state of preservation. In addition, the heat treatment at high temperatures, such as UHT milk, reduces the microbial load but does not alter the concentration of lactic acid, which thus becomes an indicator of the “history” of the product. The test can also be run on derivatives in powder (whey, milk, additives) after reconstitution in water.

Analyzers for determining L-Lactic acid in milk and dairy products


  CDR FoodLab Touch version for performing a range of tests in milk and a variety of dairy products CDR FOODLAB TOUCH CDR FoodLab Touch version for performing a range of tests in milk and a variety of dairy products CDR FOODLAB JUNIOR
Analyses e-Fructosyl Lisine
L-Lactic Acid
Alkaline phosphatase (ALP)
Hydrogen peroxide
Urea Milk Nitrogen (MUN)
Peroxide value (PV)
Free Fatty Acids (FFA)
Configuration with tailored panel of analyses
Simultaneous Sample Analyses 16 3
Multiple Analyses on a Sample si

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.


Test type: End Point
Time of test: 8 minutes:
It is possible to carry out several test sessions with a maximum of 16 samples.

Test principle

Ac.L-Lactic + der. Fenolico lactic acid reaction chinoneimina + H2O

L-Lactic acid is oxidized to pyruvate by an enzymatic reaction that produces H2O2. H2O2, in the presence of peroxidase and a phenolic derivate, forms a colored complex whose intensity was read at 545nm and is directly proportional to the concentration of L-lactic acid in the sample.

Calibration curve

Comparative tests on samples of whole milk between the reference method and the CDR FoodLab method, performed in a leading company in production of milk, confirmed a very good alignment between the two systems.

Lactic acid test in milk: FoodLab vs Reference Method


Reagent test kit *300075 suitable for 100 tests, contains:

  • 1 box includes: 5 x reagent test kit *300076.

Reagent test kit *300076, suitable for 20 tests, contains:

  • R1: 2 packages with 10 pre-filled cuvettes with 1 mL of buffer.
  • R1a: dropper with an activator.
  • R2: dropper with enzymatic solution.


Use milk as is
Diluted samples: yogurt.
Homogenized samples in a diluted soda solution: cheese, mozzarella, ricotta.

Analisys Measuring range Sample volume Resolution Repeatability
L-lactic acid milk 2 – 250 ppm 100 µL 1 ppm 5 ppm
L-lactic acid cream 1,5 – 150 ppm 100 µL 1 ppm 3 ppm
L-lactic acid ricotta 0,02 – 0,43 g/100g 50 µL 0,01 g/100g 0,03 g/100g
L-lactic acid mozzarella 0,1 – 1,5 g/100g 100 µL 0,1 g/100g 0,05 g/100g
L-lactic acid yogurt 0,01 – 1,75 g/100g 100 µL 0,01 g/100g 0,05 g/100g

For samples with a value of lactic acid >200 ppm (milk) or >150 ppm (cream) use half of the sample volume (50 μL) and multiply the result by 2.

Reagent developed by CDR S.r.l - ISO 9001 certified company


Click and Discover more about CDR FoodLab: Tests in few minutes, reference methods compliant. Easy to use also by unskilled staff

L-Lactic acid was last modified: December 2nd, 2016 by CDR s.r.l.