Determination of Citric acid in cider
Citric acid is an organic acid found in fruit and fruit juices used in cider production. It can also be formed by yeasts during fermentation and, therefore, measuring it can be an important indication for the producer.
Method
Test type: End Point.
Testing time: 6 minutes.
Are possible test sessions with several samples, up to 16 for CDR CiderLab and 3 tests for CDR CiderLab Junior.
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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
Through an enzymatic reaction, citric acid is converted into oxalacetate and then into malate that reacts with NADH producing NAD+. The reduction of absorbance, measured at 366 nm (end-point), of the NADH solution is proportional to the quantity of citric acid present in the sample.
Calibration curve
The calibration curve of the CDR CiderLab instrument, performed using standards with a known concentration of citric acid, confirmed an excellent linearity of the system over the entire measurement range.
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Reagent test Kits
Measuring range
| Analyses | Measuring range | Resolution | Repeatability |
|---|---|---|---|
| Citric Acid [0.1-1.0] g/L | 0.1 - 1 g/L | 0.01 g/L | 0.04 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