Musts and wines from grapes affected by grey mould may contain varying concentrations of gluconic acid depending on the severity of the attack. In fact the enzymatic action of mould on grapes results in the generation of gluconic acid due to the oxidation of glucose.
This situation leads to deterioration of the health status of the must and possible difficulties in triggering of alcoholic fermentation.
The Analyzers CDR WineLab® for determining gluconic acid 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) Copper Catechins Gluconic Acid Acetaldehyde (Ethanal) pH Total Polyphenols Index Glycerol Colour (tonality and intensity) Total Polyphenols (Folin Ciocalteu) Anthocyanins 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 |  |
– |
Method
Test type: End Point.
Time testing: one test 6 minutes – 50 Test/Hour.
Analysis sessions with multiple samples up to a maximum of 16 are possible.
Correlation with the reference method
The correleation curve of CDR WineLab®, obtained using reference methods.
Test Principle
Gluconic acid is phosphorylated by the action of a suitable enzyme in the presence of ATP.
The adduct, formed through the action of NAD+, results in the formation of NADH in the ratio of 1:1 with gluconic acid present in the sample. The reaction, at end point, is measured at 366 nm and an increase in absorbance is directly proportional to the concentration of gluconic acid.
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. *300583 : 10 tests
Code. *300580 : 100 tests (10 packages of 10 tests)
The reagents have a shelf-life of 6 months.
Analyses of gluconic acid for optimum management of alcoholic fermentation
Check out why, especially in cold and rainy vintages, gluconic acid analysis is a fundamental tool for better management of the alcoholic fermentation, avoiding the deterioration of the health status of the must, the difficulty in protecting against oxidation and the depletion of nutrient resources for yeasts. Download the paper: VINIFICATION IN THE ERA OF GLOBAL WARMING
Processing Sample
MUST
For precise and repeatable analysis on the must, the sample must be degassed with the relevant ultrasonic bath and spun with the mini-centrifuge to separate the solid particles present in the solution.
WINE
Take the sample in its unaltered state (possibly degas with the relevant ultrasonic bath
Measuring Range
| Test | Measuring range | Resolution | Repeatability |
|---|---|---|---|
| Gluconic acid | 0,05 – 3 g/L | 0,01 | 0,02 g/L |
