Determination of L-Malic acid in cider
By analyzing L-Malic acid and L-Lactic acid, it is possible to assess the correct progress of the malolactic fermentation.
Method
Sample treatment
If necessary, the sample shall be degassed using the specific ultrasonic bath (code 222062). In case of tests performed on must, the sample shall be centrifuged (code 222061) or filtered (code 300210).
Principle of the test
L-Malic acid in presence of NAD+ 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.
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Calibration curve
The calibration curve of CDR CiderLab, obtained using reference methods, confirms the excellent linearity of the system over the whole testing range.
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Reagent test Kits
Code*300340: 10 tests
Measuring range
| Analyses | Measuring range | Resolution | Repeatability |
|---|---|---|---|
| L-Malic acid [0.1-10] g/L | 0.1 - 10 g/L | 0.01 g/L | 0.11 g/L |
The Analyzers for process and quality control in cider production
CDR CiderLab
Complete analysis panel, supplied already configured
Up to 16 determinations simultaneously
Possibility of carrying out analyses of the same sample
Integrated printer
Full connections (LAN - USB - Bluetooth barcode/QR code reader)
CDR CiderLab Jr
Partial analysis panel, customisable configuration
Up to 3 determinations simultaneously
Wireless connection to external printer
USB connections