Influence Of Mannoprotein On Wine’s Malolactic Fermentation

Mannoprotein is an important additive during winemaking. It has been recognized to have many positive enological properties such as keeping protein stability, inhibiting tartar crystallization, combined with tannin decreasing astringency, promoting the release of aroma components, improving the foam quality of sparkling wine, stimulating malolactic fermentation(MLF). In order to study the function and mechanism of mannoprotein, some researches have developed at home and abroad. However, the effect of commercial mannoprotein made in China on O.oeni has not been studied clearly, so the research palys an important role in guiding for practice.In this paper, mannoprotein MP60 was used to study the influence on the growth of O.oeni in model wine mediums. In addition, changes of total acid, total phenols, tannins, aroma and other indexes were quantitative determined to research the effects of mannoprotein on wine’s MLF through two addition time: at later alcoholic fermentation(AF), after AF and before MLF. The conclusions were summarized as follows:1. According to the changes of biomass, L-malic acid in model wine mediums with O.oeni SD-2a, O.oeni HB-2b and O.oeni 31-DH, we found that mannoprotein promote the growth of the three strains, and there was a positive correlation between biomass and dosages of mannoprotein. In addition, with the increase of adding amount, deacidification increased. But the effect of mannoprotein on O.oeni showed strain-specificity. These demonstrated that mannoprotein could promote the growth of O.oeni, increased its biomass and then improved the comsumption of L- malic acid.2. Mannprotein added to conduct wine’s MLF reduced the loss of total phenols, total anthocyanins, monomeric anthocyanins and polymeric anthocyanins during fermentation, and improved deacidification rate. When added after AF and before MLF, mannprotein shortened the duration of MLF. While it may cause unpleasant aroma for higher acids components. When added at later AF, it promoted the release and synthesis of ester, aldehyde ketone, benzene and terpene among aroma components, enhanced floral and fruity characteristics.