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 Yeast Assimilable Nitrogen Test (YAN) in Wine and Must

The system is supplied pre-calibrated and ready for use.
Results are expressed in accordance with the reference method.
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	Wine and Must: Alcohol by Volume Acetic acid (volatile acidity) Fermentable Sugars Total Acidity L-Lactic Acid L-Malic Acid Free sulfur dioxide Total sulfur dioxide Yeast Assimilable Nitrogen (YAN) Galacturonic Acid Calcium Copper Catechins Gluconic Acid Acetaldehyde (Ethanal) pH Total Polyphenols Index Glycerol Colour (tonality and intensity) Total Polyphenols (Folin Ciocalteu) Anthocyanins Extraction on Grapes Total Anthocyanins Polymerised Anthocyanins HCl Index Tannins	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.
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

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 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.
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 Nitrogen.

Analyses of yeast assimilable nitrogen (YAN) for optimum management of alcoholic fermentation

Check out why, especially in hot and dry vintages, YAN analysis is a fundamental tool for better management of the alcoholic fermentation, allowing for prudent planning of yeast nutrition and thus avoiding dangerous stucks fermentation. Download the paper: VINIFICATION IN THE ERA OF GLOBAL WARMING

Processing Sample

If necessary, the sample shall be degassed using the specific ultrasonic bath. In case of tests performed on must, the sample shall be first centrifuged.

Measuring Range

Test	Measuring range	Resolution	Repeatability<
Inorganic Nitrogen	30 – 300 mg/L di N inorganic	1	2 mg/L
Organic Nitrogen	30 – 300 mg/L di N organic	1	2 mg/L

Click and Discover more about CDR WineLab^®: analysis system fast, simple to use and reliable for determining multiple parameters in wine and must