Yeast Mannoproteins
Yeast mannoproteins are added to wine to inhibit the formation of potassium bitartrate crystals which are commonly formed in bottled wine. The presence of potassium bitartrate crystals in wine is not a safety or wine quality issue but rather one of aesthetics. Recognised by the OIV, yeast mannoproteins are permitted for use in grape wine in over 50 countries worldwide.
Mannoproteins are extracted from Saccharomyces cerevisiae yeast cell walls by physico-chemical of enzymatic methods. Mannoproteins are different structures depending on their molecular weight, their degree and type of glycosylation, and their load size. Depending on their extraction mode, they have different tartaric and/or protein stabilisation of wine.
Mannoproteins are found in powder form, usually microgranulated, white or beige in colour, odorless, or in a colloidal solution , yellow in colour, translucid. For further substance information, please see the International Oenological Codex.https://www.oiv.int/public/medias/4286/e-coei-1-manpro.pdf
Synonym(s): Not available at this time
CAS Number: Not available at this time
E Number: Not available at this time
INS Number: Not available at this time
International Organisations
Codex Alimentarius
-Classification, Food Category, Functional Class and Recommended Usage is not available at this time.
International Organisation of Vine and Wine (OIV)
-Classification, Food Category, Functional Class and Recommended Usage is not available at this time.
FIVS
Classification Category 4 – Not naturally occurring in grapes and treatment residual in wine
As outlined in the OIV’s International Code of Oenological Practices, Yeast mannoproteins is used: Depending on their extraction mode, they have different tartaric and/or protein stabilisation of wine.
Usage in Winemaking:
Yeast mannoproteins are added to wine to inhibit the formation of potassium bitartrate crystals which are commonly formed in bottled wine. The presence of potassium bitartrate crystals in wine is not a safety or wine quality issue but rather one of aesthetics. Mannoproteins are extracted from purified yeast (Saccharomyces cerevisiae) cell walls, via enzymatic extraction using β-glucanase. The resulting mannoprotein preparation has an apparent molecular weight of around 40 kDa. The β-glucanase enzyme hydrolyses the yeast cell wall which then allows the mannoproteins to be solubilised. Subsequently, the enzyme digest is ultrafiltered to remove insoluble cell wall material and the mannoprotein preparation is concentrated. Wine is treated with yeast mannoproteins in the range of 100-300 mg/l (the maximum proposed treatment level being 300 mg/l). Additionally, yeast mannoproteins increase the mouthfeel of a wine and also contribute to malolactic fermentation bacterial growth during secondary fermentation.
See FIVS technical papers for more information - click here.
