Determination of the Galacturonic Acid in must and wine
Together with gluconic acid, uronic acids such as galacturonic acid and glucuronic acid are products that form in botrized grapes and that combine sulphur dioxide therefore lowering the level of free SO₂ with the same added metabisulphite. Knowing the concentration of these compounds, both in red and white wines, is therefore very important in order to establish the most suitable oenological protocol.
Method
Sample treatment
Wine is analyzed as it is. If necessary (sparkling or fermenting wine), 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
Uronate dehydrogenase reacts with galacturonic and glucuronic acid to develop NADH, which is directly proportional to the concentration in the sample expressed in g/L.
Calibration curve
The calibration curve of the CDR WineLab® instrument, performed using standards with a known concentration of galacturonic acid, confirmed an excellent linearity of the system over the entire measurement range.
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Reagent test Kits
Code*301045: 10 tests
Measuring range
| Analyses | Measuring range | Resolution | Repeatability |
|---|---|---|---|
| Galacturonic Acid [0.1-2 g/L] | 0.1 - 2 g/L | 0.01 g/L | 0.04 g/L |
| Galacturonic Acid [0.03-0.5 g/L] | 0.03 - 0.5 g/L | 0.01 g/L | 0.02 g/L |
Analyzers for process and quality control in winemaking
CDR WineLab®
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 WineLab® Jr
Partial analysis panel, customisable configuration
Up to 3 determinations simultaneously
Wireless connection to external printer
USB connections