Determination of Alcohol by Volume (ABV) in Kombucha
The symbiotic culture of acetic bacteria and yeasts immersed in the sweetened tea infusion triggers an alcoholic fermentation that can bring about variable alcohol concentrations from traces by approximately one percentage point.
Normally the majority of kombucha on the market have an alcohol content that is below 0.5%. The measurement of this parameter is very important for legal purposes as a concentration above 1.2% requires registration of the beverage produced as "alcoholic". There are also products called “hard kombucha”, with a higher alcohol concentration.
Method
Sample treatment
For precise and repeatable analysis, degas the sample using the ultrasonic bath (code 222062). If necessary, the sample should be centrifuged (code 222061) or filtered (code 300210). The analysis requests a rapid and simple dilution of the sample.
Principle of the test
Ethanol, in the presence of NAD+ , is oxidized by enzymatic route to acetaldehyde with the consequent production of NADH. The increase in absorbance, measured at 366 nm at the end-point, is directly proportional to the concentration of ethanol in the sample. The result is expressed in %v/v.
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Calibration curve
The calibration curve of the CDR KombuchaLab instrument, obtained by comparing the CDR method with the distillation method for determination of the alcohol content, confirmed an excellent linearity of the system over the entire measurement range.
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Reagent test Kits
Code*300740: 100 tests
Measuring range
| Analyses | Measuring range | Resolution | Repeatability |
|---|---|---|---|
| Alcohol by volume [0.1-1.8] % | 0.1 - 1.8 %vol | 0.01 %vol | 0.02 %vol |
| Alcohol by volume [1-10] % | 1 - 10 %vol | 0.1 %vol | 0.1 %vol |
CDR KombuchaLab
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 KombuchaLab Jr
Partial analysis panel, customisable configuration
Up to 3 determinations simultaneously
Wireless connection to external printer
USB connections