Published in Scientific Papers. Series B, Horticulture, Vol. LXVI, Issue 1
Written by George Adrian COJOCARU, Arina Oana ANTOCE
Polyvinilpolypirrolidone (PVPP) and potassium caseinate (KCas) are the standard treatments used for removing before fermentation a part of the polyphenolic compounds from white grape musts, in order to prevent their oxidation in the resulted wines. As PVPP is a synthetic polymer and KCas is an animal protein with allergenic potential, in line with the movements toward more natural and vegan products, alternative fining agents are being proposed in the form of vegetal proteins. In this study the fining potential of pea and potato proteins was evaluated compared to PVPP and KCas, by determining the change in colour (CIELab parameters) and the amount of total polyphenols removed from the wines of Welsch Riesling. Each fining agent was applied to the must before fermentation in doses of 10, 20 and 30 g/hl and their effect in wine was analysed. The treatments applied tend to reduce wine colour yellowness (parameter b), shift more toward greener (parameter a), and decrease colour saturation (C). For each treatment the parameters determined spectrophotometrically were in direct correlation with the dose used, even though the total colour differences (ΔE values) of the musts were not perceivable by the naked eye, in the young wines. However, clarification of must with any fining agent significantly removed a part of the total polyphenols in a dose-dependent manner, the efficiency of the fining agents being in the following order: PVPP>Pea>Potato=KCas>Control. To also evaluate the economic impact of using these new alternatives, sensory analysis was also carried out and the costs of treatments were determined.
[Read full article] [Citation]
