Kombucha

The symbiotic culture of acetic and yeast bacteria immersed in the sweetened tea infusion triggers an alcoholic fermentation. This fermentation can be favoured by the presence of assimilable nitrogen (organic and inorganic) which can be added before fermentation starts. The quantity of assimilable nitrogen can also be controlled during the fermentation process itself in order to guarantee a complete evolution of the fermentation avoiding undesired organoleptic deviations in the finished product.

Determination of Yeast Assimilable Nitrogen (YAN) in Kombucha

CDR KombuchaLab the easy-to-use analysis system to optimise your kombucha production process by obtaining results in real time.

Test type: End Point. Time testing: [uni]. Analysis sessions with multiple samples are possible for up to a maximum of 16 tests for CDR KombuchaLab and 3 tests for CDR KombuchaLab Junior.<h3>Sample treatment</h3>For precise and repeatable analysis, degas the sample using the ultrasonic bath (code 222062) and clarify it, if necessary, using the centrifuge (code 222061).

Method

Organic nitrogen (α – amino nitrogen) and inorganic nitrogen (ammonium ion) are determined separately. In the presence of ammonium and NADH the glutamate dehydrogenase (Gl-DH) reacts with α-keto glutarate to form L-glutamic acid and NAD+. The decrease in absorbance, measured at 366 nm (end-point), of the NADH solution is proportional to the quantity of Inorganic Nitrogen present in the sample expressed in mg/L.&nbsp;&nbsp;The Organic Nitrogen (α-amino) reacts in the presence of N-acetyl-L-cysteine with the o-phthalaldehyde forming an isoindolic derivative. The difference in absorbance, measured at 366 nm (end-point) is correlated with the quantity of organic nitrogen expressed in mg/L.

Test Principle

The calibration curve of the CDR KombuchaLab&nbsp;instrument, carried out using the known concentration of isoleucine for the organic nitrogen and ammonium chloride for inorganic nitrogen, confirmed an excellent linearity of the system over the entire measurement range.

Calibration Curve  

Calibration curve of the CDR KombuchaLab instrument, carried out using standards with a known concentration of isoleucine for organic nitrogen. R² = 0.9911

Calibration curve of the CDR KombuchaLab instrument, carried out using standards with a known concentration of ammonium chloride for inorganic nitrogen. R²=0.9945

Calibration curve of the KombuchaLab CDR instrument, carried out using standards with a known concentration of ammonium chloride for inorganic nitrogen. R²=0.9945

Reagent test Kits

Please note: Organic (*301430, *301435) and Inorganic Nitrogen (*301440, *301445) kits must be used together.

Measuring range

CDR KombuchaLab: the easy-to-use analysis system to optimise your kombucha production process by obtaining results in real time. Top version

CDR KombuchaLab

CDR KombuchaLab: the easy-to-use analysis system to optimise your kombucha production process by obtaining results in real time. Junior version