RESOLUTION OIV-OENO 674-2022

UPDATE TO THE MONOGRAPH ON YEAST EXTRACTS CONTAINING MANNOPROTEINS (COEI-1-MANPRO)

IMPORTANT: This resolution modifies the following monograph and resolution: COEI-1-MANPRO OENO 26/2004

THE GENERAL ASSEMBLY,

IN VIEW OF Article 2, paragraph 2 iv of the Agreement of 3 April 2001 establishing the International Organisation of Vine and Wine,

CONSIDERING the work of the “Specifications of Oenological Products” Expert Group,

DECIDES, at the proposal of Commission II “Oenology”, to update Resolution OENO 26-2004 and, accordingly, Monograph COEI-1-MANPRO in Chapter I of the International Oenological Codex as follows:

UPDATE TO THE MONOGRAPH ON YEAST EXTRACTS CONTAINING MANNOPROTEINS (E-COEI-1-MANPRO)

The title of the monograph is changed to: “Yeast extracts containing mannoproteins”.

The following sentence is to be added to point 3.2:

Their water solubility is determined by comparing the total dry matter (DM) with the insoluble DM that remains after a hot wash, according to the method described in Annex 2. The percentage of insoluble DM should be less than or equal to 1% ± 0.5.

Point 3.3. is to be deleted.

Point 5 is modified as follows (italic part added):

Solid mannoproteins must be stored away from humidity in a sealed pack in a temperate room.

The following Annex 2 is to be added to the monograph (Annex 2):

ANNEX 2 DETERMINATION OF THE PERCENTAGE OF INSOLUBLE DRY MATTER

1.      Principle

The analysis consists of comparing the total dry matter (DM) of the yeast mannoprotein preparation with the insoluble DM that remains after a hot wash.

2.      Material and reagents

2.1.      4200 rpm (6000g) Centrifuge and accessorie

2.2.      Scales with 0.1 mg precision

2.3.      Oven at 105 °C +/- 1 °C

3.      Procedure

Obtaining the insoluble part of the yeast mannoprotein preparation

• Place approx. 10 g of yeast mannoprotein preparation, previously placed in an oven at 105 °C until constant weight, in a tared centrifuge bucket. Note the exact weight, which will be referred to as M1.
• Suspend in hot water (70-80 °C).
• Stir.
• Centrifuge for 10 min at 4200 rpm (6000g).
• Discard the supernatant, stir again into hot water and centrifuge for 10 min at 4200 rpm.
• Carry out the procedure a third time.
• Place the tared centrifuge bucket containing the centrifugation pellet in an oven at 105 °C until constant weight. Note the weight. M2 is the weight of the residue of yeast mannoproteins preparation that make up the insoluble DM.

4.      Calculations

Insoluble dry matter percentage (Insoluble DM %) = (M2/M1) x 100