Analysis of Grape Proteins from Wines by Perfusion Reversed-Phase High-Performance Liquid Chromatography

Concentration and characteristics of grape proteins can strongly influence the quality of the wine, therefore the availability of reliable information of these biomolecules are crucial. This paper describes, for the first time, a simple and fast reversed-phase high-performance liquid chromatography (RP-HPLC) method enabling the separation and quantification of grape proteins from wines. Several factors, such as gradient elution, column temperature, detection wavelength, type and concentration of ion-pairing agent and the conditions for the sample preparation were optimised. The proposed method enables a separation of the grape proteins from wines in only 7 min using a linear binary gradient of water/acetonitrile/0.1 % trifluoracetic acid in four steps at a flow rate of 3 mL/min with a column temperature of 65 °C and UV detection at 210 nm. The method was validated and applied to the quantification of grape proteins in white and rosé wines. The potential of the method was also demonstrated by its application to the differentiation of wine samples with different aging over lees and grape varieties.