Determination of Yeast Assimilable Nitrogen (YAN) in Must
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 must as ammonium ion (NH4+) and organic nitrogen constituted by a-amino nitrogen of amino acids.
The CDR WineLab® analytical method for the analysis in wine and must:
- it is much easier than the method of the formol number generally used and it can be done in autonomous way in winery 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 must, and not assimilated by yeasts.
Inorganic nitrogen (ammonium) is determined with the enzymatic way whereas organic nitrogen is determined with the o-phthalaldehyde method.
The Analyzers CDR WineLab® for determining Yeast Assimilable Nitrogen (YAN) in Wine and Must
The system is supplied pre-calibrated and ready for use.
Results are expressed in accordance with the reference method.
It is also possible to standardize the system using samples with a known titration.
The reagents have a shelf-life untill 18 months
The analytical methods are simple: the system does not require an equipped laboratory or skilled staff.
 CDR WINELAB® |  CDR WINELAB® JUNIOR | |
|---|---|---|
| Analyses | Fermentable Sugars Total Acidity Acetic Acid L-Lactic Acid L-Malic Acid Malolactic Fermentation Alcohol Free sulfur dioxide (Free SO2) Total sulfur dioxide (Total SO2) pH Yeast assimilable nitrogen (YAN) Gluconic Acid Glycerol Polyphenols TPI – Total Polyphenols Index Acetaldehyde (Ethanal) Anthocyanins Catechins Colour intensity and tonality Copper | Configuration with tailored panel of analyses |
| Simultaneous Sample Analyses | 16 | 3 |
| Multiple Analyses on a Sample |  | – |
Inorganic Nitrogen
Method
Test type: End Point.
Time Testing: one test 4 minutes – 60 Test/Hour.
Are possible test sessions with several samples, up to a maximum of 16.
Calibration Curve
The calibration curve of CDR WineLab® for the analysis of Yeast Assimilable Nitrogen Inorganic in must, obtained using reference methods, confirms the excellent linearity of the system over the whole testing range.
Reagent test Kits
The reagents are packaged in foil pouches containing 10 tubes useful to perform 10 analyses.
This is the minimum package that allows the use of CDR systems even to those who need to make a few analyses, thus not wasting reagents.
There are also boxes of 100 tests, however, packaged in 10 bags of 10 tubes containing the reagent.
Code. *300435: 10 tests
Code. *300430: 100 tests (10 packages of 10 tests)
The reagents have a shelf-life of 6 months
Test Principle
a-cheto glutarate + NADH + NH4+
Acid L-glutammic + NAD+ +H2O
The ammonium reacts by enzimatic path-way with NADH and a-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.
Organic Nitrogen
Method
Test type: End Point.
Time testing: one test 4 minutes – 60 Test/Hour.
Are possible test sessions with several samples, up to a maximum of 16.
Calibration Curve
The calibration curve of CDR WineLab® for the analysis of Yeast Assimilable Nitrogen Organic in must, obtained using reference methods, confirms the excellent linearity of the system over the whole testing range.
Reagent test Kits
The reagents are packaged in foil pouches containing 10 tubes useful to perform 10 analyses.
This is the minimum package that allows the use of CDR systems even to those who need to make a few analyses, thus not wasting reagents.
There are also boxes of 100 tests, however, packaged in 10 bags of 10 tubes containing the reagent.
Code. *300435: 10 tests
Code. *300430: 100 tests (10 packages of 10 tests)
The reagents have a shelf-life of 6 months
Test Principle
The a-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.
Processing – Sample Volume – Measuring Range
| Test | Measuring range | Sample volume | Resolution | Repeatability |
|---|---|---|---|---|
| Inorganic Nitrogen | 30 – 300 mg/L di N inorganic | 10 µL of wine | 1 | 2 mg/L |
| Organic Nitrogen | 30 – 300 mg/L di N organic | 20 µL of wine | 1 | 2 mg/L |
