Monitorizarea fermentaţiei malolactice la vinurile roşii obţinute în Podgoria Miniş-Măderat

Abstract

The paper has proposed to realize an interphasic control ao the malolactic fermentation at rwd wines obtained in Minis – Maderat vineyard, harvest 2006. In order to do so, the following goals were imposed: - the estimation of the malic acid degradation through paper chromatography (Michaud method) and enzymatic measuring - enzymatic measuring of the lactic acid made by the malolactic fermentation - establishment of the lactic acid nature made b y the malolactic fermentation - monitoring the bacterial population evolution during the malolactic fermentation through the direct numbering methods (with Thoma camera) and indirect (through cultural examination) The results show that the moment of the malolactic fermentation finalization moment is influenced by the initial lactic bacterial number from wine. The nature of the lactic acid made by the malolactic fermentation (L or D form) show us indications concerning the lactic bacteria species implied in the malolactic fermentation of wines and the biochemical metabolism mechanism of the malic acid. Precisely determining, the concentrations of the malic and lactic acid from wines and by advisable utilization of the malolactic bacterial starter cultures we can initiate and finalize a malolactic fermentation in safe conditions, increasing the microbiological stability of the wine and improving the sensorial profile of the wine.