The content of organic acids in general, as of L-Malic acid in particular, plays a fundamental role in determining the beneficial effects of kombucha. Moreover, as L-Malic acid contributes to the organoleptic qualities of the drink, it is important to monitor its levels in order to evaluate the quality of the final product.
CDR KombuchaLab: Instruments for the determination of L-Malic Acid in Kombucha
The instruments are supplied pre-calibrated and ready to use.
The results are expressed according to the reference method.
The methods are simple: there is no need for an equipped laboratory or for specialist personnel.
 CDR KombuchaLab |
 CDR KombuchaLab Junior |
|
|---|---|---|
| Analyses | Kombucha: Alcohol by Volume Total Polyphenols Fermentable Sugars Acetic Acid Gluconic Acid Galacturonic Acid L-Malic Acid Total Lactic Acid Glycerol Yeast Assimilable Nitrogen (YAN) |
Configuration with tailored panel of analyses |
| Simultaneous Sample Analyses | 16 | 3 |
| Multiple Analyses on a Sample |  |
– |
Method
Test type: End Point.
Time testing: 4 minutes.
Are possible test sessions with several samples, up to 16 tests for CDR KombuchaLab and 3 tests for CDR KombuchaLab Junior.
Test Principle
L-Malic acid + NAD+ 
Oxaloacetate + NADH
L-Malic acid is oxidized in an alkaline environment through an enzymatic reaction and converted into oxaloacetic acid, which is turn produces NADH. The increase of absorbance, measured at 366 nm (end-point), is directly proportional to the concentration of L-Malic acid in the sample.
Calibration Curve
The calibration curve of CDR KombuchaLab, obtained using reference methods, confirms the excellent linearity of the system over the whole testing range
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 *300340: 10 tests
Code *300332: 100 tests
The reagents have a shelf-life of 15 months
Processing of Sample Volume
For precise and repeatable analysis, the sample must be degassed with the appropriate ultrasonic bath (code 222062) with the mini-centrifuge (code 222061) to separate the solid particles present in the solution.
Measuring Range
| Test | Measuring Range | Resolution | Repeatability |
|---|---|---|---|
| L-Malic acid [0.05-5] g/L | 0.05 - 5 g/L | 0.01 g/L | 0.08 g/L |
