Alginates, Potassium

Potassium Alginates are commonly used in wine as clarifying agents to remove solids from solution, or may also entrap bind enzymes which can then be filtered out of the finished wine. It is best used in wines with high acid and low pH and is usually utilised in conjunction with gelatin or bentonite. Potassium alginates are permitted for use in grape wine in over 55 countries worldwide. 

Alginic acid is a colloidal polysaccharide extracted from various varieties of brown algae in particular from Laminaria. The monomers constituting the a-L-glucuronic acid and b- D-mannuronic acid are bound in pairs as connections of the type. 

A suspension of 3% alginic acid in water has a pH ranging between 2 and 3.5. An alginic acid solution of 5 g/l in sodium hydroxide (dissolve 4.3 g of sodium hydroxide in water and complete to 100 ml) precipitate in gelatinous form by adding a fifth of volume of a 2.5% solution of calcium chloride. Furthermore, an addition of a half volume of a solution saturated with ammonia sulfate to the solution previously described does not cause any turbidity. These two tests can be used to differentiate alginic acid from other polysaccharides that may be used in foodstuffs or pharmaceuticals. For further substance information, please see the International Oenological Codex.