150 R. Marchal and P. Jeandet
Ta b l e 5. 2Tartrate stabilization of various white wines by adding MannostabTMas determined by
visual observations of potassium bitartrate crystallization within six days at− 4 ◦C (redrawn with
permission from Moine-Ledoux et al. 1997)
Wines MannostabTM(g/hL)
0 152025301996 Blanc de Blancs Visual test + 000 0
K+(mg/L) 52 72 17 0 0
Whitevin de table Visual test + 000 0
K+(mg/L) 104 53 33 0 0
1996 white Bordeaux Visual test + 000 0
K+(mg/L) 62 21 0 0 21
1996 white Graves Visual test ++ 00 0
K+(mg/L) 155 52 0 0 62
bitartrate precipitations while the same wines treated with metatartaric acid were
obviously proven to be unstable.
In other work, Moine-Ledoux et al. (1997) reported that the use of MannostabTM
at doses ranging from 15 g/hL to 25 g/hL inhibit potassium bitartrate precipitation
(Table 5.2) while excess amounts of this additive, that is 30 g/hL, are ineffective
on potassium bitartrate crystallization (Table 5.2). Within the extracts, compounds
responsible for the stabilizing effect observed were found to be highly glycosylated
mannoproteins of molecular masses ranging from 30 kDa to 40 kDa possessing a
glycosyl-phosphadityl-inositol anchor (GPI) (Moine-Ledoux and Dubourdieu 1999,
2002, 2007).
5.2.3 Use of Carboxymethylcelluloses for Stabilization of Tartrate
Salt Precipitation
Natrium carboxymethylcelluloses (CMC) are polymers ofβ-D-glucose units whose
primary or secondary alcohol groups are etherified by natrium acetate groups
(–CH 2 –COONa). This substitution is mostly 2-O- and 6-O-linked. Since CMC are
polymeric substances, they may exhibit colloid protective effects against tartrate salt
crystallization. CMC are a group of complex poorly-defined products, that is, dis-
persed polymers which are largely used in the food industry (E 468) as a thickener
and stabilizing agent for instance in ice cream. CMC are defined by their poly-
merization and substitution (that is, thenumber of primary orsecondary alcohol
groups etherified) degrees. CMC may have different degrees of substitution, but it is
generally in the range 0.6–0.95 derivatives per monomer unit. As thickeners, CMC
are known to modify a wine’s viscosity. By now, CMC have high purity (ca. 99.5%)
with a natrium content ranging from 7% to 8.9% (Maujean 2000) and their low
viscosity are no more detrimental to beverage’s viscosity. CMC are sold as powders
susceptible to absorb water in suspension in the air. For this reason, they must be
kept in a dry place.