Anthocyanins Extraction on Grapes
Anthocyanins are polyphenols present in the skin of grapes, whose colour changes according to the acidity of the surrounding environment. Anthocyanins are not very soluble in must and water, but very soluble in alcohol produced during fermentation. The colour of the future wine therefore depends on the degree of ripeness and on the duration of maceration of the skins. In addition, the concentration of polyphenols strongly influences the stability of a red wine during ageing. Therefore, in the case of a red wine, it is important to take into account the phenolic maturity of the grapes when choosing the harvest period.
The method considered to be the reference method for the determination of phenolic maturity (Glories method) is very time-consuming because it requires a long extraction and sample preparation phase. In addition, it is necessary that the analyses be carried out by an operator specialised in laboratory techniques.
The CDR WineLab® method for the determination of Anthocyanins in grapes and therefore of phenolic maturity optimizes the Glories method in order to make it even simpler, faster and more accurate.
This analysis can also be performed on wine vinegar.
Method
Test Principle
The total Anthocyanins present in the wine in must and grapes, in a very acidic environment and through the action of a concentrated SO₂-based reagent, undergo a discoloration that is measured at 520 nm at end point. This discoloration is directly proportional to the concentration in the sample expressed in mg/L.
Correlation curve
The correlation curve of the CDR WineLab® instrument, carried out in comparison to the Glories reference method, confirmed an excellent system linearity over the entire measuring range.
Reagent test Kits
Measuring range
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The Analyzer for for process and quality control in winemaking
CDR WineLab®
- 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)