RESOLUTION OIV-OENO 465-2012

SUPPLEMENT TO THE METHOD FOR DETERMINING DRY EXTRACT (OIV-OENO 387/2009) (OIV-MA-AS2-03B)

The GENERAL ASSEMBLY,

GIVEN Article 2, paragraph 2 iv of the Agreement dated April 3, 2001 which led to the establishment of the International Organization of Vine and Wine,

Upon proposal of the Sub-Commission “Methods of Analysis”,

CONSIDERING the change to the “Total dry extract” method adopted by the OIV with resolution OIV-Oeno 387-2009 and which appears in the “Compendium of International Methods of Wine and Must Analysis” (OIV-MA-AS2-03B).

CONSIDERING the opportunity to provide the definition of the “sugar inversion” process.

DECIDES to incorporate the “Total dry extract” method that appears in the Compendium of International Methods of Wine and Must Analysis (MA-AS2-03B) with the following definition:

"Inversion refers to the process that leads to the conversion of a stereoisomer into compounds with reverse stereoisomerism. In particular, the process based on splitting sucrose into fructose and glucose, carried out by keeping acidified solutions containing sugars (100 ml solution containing sugars + 5 ml concentrated hydrochloric acid) for at least 15 min at 50°C or above in a water bath (the water bath is maintained at 60°C until the temperature of the solution reaches 50°C), is called sugar inversion. The final solution is laevo-rotatory  due to the presence of fructose, while the initial solution is dextro-rotatory  due to the presence of sucrose."