Yeast Assimilable Nitrogen (YAN)

Yeast Assimilable Nitrogen (YAN) is a fundamental parameter to manage correctly the alcoholic fermentation. It is constituted by two components: the inorganic nitrogen present in juice as ammonium ion (NH4+) and organic nitrogen constituted by a-amino nitrogen of amino acids.

The CDR CiderLab analytical method for the analysis in cider:

  • it is much easier than the method of the formol number generally used and it can be done in autonomous way at production line in real time without using toxic substances and with a simple photometric reading.
  • it allows the determination of the two nitrogen parameters separately, giving the possibility of making any corrections in a way more accurate than the analysis with formol number;
  • The result is not influenced by the presence of proline and hydroxy-proline, amino acids present in juice, and not assimilated by yeasts.

Inorganic nitrogen (ammonium) is determined with the enzymatic way whereas organic nitrogen is determined with the o-phthalaldehyde method.

Method

Test principle

Organic nitrogen test

Organic nitrogen test chemical reaction

 

The α-amino nitrogen reacts, in presence of N-acetyl-L-cysteine, with the o-phthalaldehyde to form a isoindolic derivative. The difference in absorbance, measured at 366 nm (end-point) is correlated with the amount of organic nitrogen expressed as mg / L of N.

Inorganic nitrogen test

Reazione test azonto prontamente assimilabile inorganico

The ammonium reacts by enzimatic path-way with NADH and α-ketoglutarate to give NAD+ and glutamate. The decrease in absorbance of the solution of NADH, measured at 366 nm (end-point), is proportional to the amount of ammonium nitrogen in the sample.

 

Calibration Curve

Organic nitrogen test

Cider organic nitrogen analysis calibration curve with CDR CiderLab. R²=0.9993

The calibration curve of CDR CiderLab for the analysis of Yeast Assimilable Nitrogen Organic in juice has been performed with standard solutions, realised with the addiction of known concentrations of the analyte, to the matrix involved in the method. The curve obtained confirms the excellent linearity of the method over the whole testing range.

Inorganic nitrogen test

Cider inorganic nitrogen analysis calibration curve with CDR CiderLab. R²=0.9972

The calibration curve of CDR CiderLab for the analysis of Yeast Assimilable Nitrogen inorganic in juice has been performed with standard solutions, realised with the addiction of known concentrations of the analyte, to the matrix involved in the method. It confirms the excellent linearity of the system over the whole testing range.

 

 

Reagent test Kits

Measuring range

AnalysesMeasuring rangeResolutionRepeatability

The Analyzers for process and quality control in cider production

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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)
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CDR CiderLab Jr

  • Partial analysis panel, supplied configured with 3 analyses of your choice, implementable
  • Up to 3 determinations simultaneously
  • Wireless connection to external printer
  • USB connections