E353 - Metatartaric acid

Origin

Metatartaric acid (E353) is a complex mixture of tartaric acid esters formed by the controlled heating of tartaric acid. It is not a naturally occurring substance but is synthesized for use as a food additive. The production process involves the esterification of tartaric acid molecules, resulting in polymers of varying chain lengths. These polymers are responsible for its unique properties in food applications.

Usage

Metatartaric acid is primarily used as a crystallization inhibitor, particularly in wine. It prevents the precipitation of tartrates (tartaric acid salts) during wine storage and bottling, which can appear as unsightly crystals. It is also used in some fruit juices and other beverages for the same purpose. The additive works by interfering with the nucleation and growth of tartrate crystals, keeping them dissolved in the liquid. The typical usage level in wine ranges from 10 to 100 mg/L. Its effectiveness decreases over time due to hydrolysis, which breaks down the ester bonds and converts it back to tartaric acid. Therefore, it is not a permanent solution for tartrate stabilization.

Side Effects

Metatartaric acid is generally considered safe for consumption at the levels typically used in food and beverages. Tartaric acid itself is a naturally occurring acid found in many fruits. The Joint FAO/WHO Expert Committee on Food Additives (JECFA) has established an Acceptable Daily Intake (ADI) of 'not specified' for tartaric acid and its salts, which includes metatartaric acid. This means that, based on available data, the use of metatartaric acid at levels necessary to achieve its intended effect does not pose a health risk. However, excessive consumption of highly acidic foods or beverages could potentially lead to dental erosion or gastrointestinal discomfort in sensitive individuals. No specific side effects directly related to metatartaric acid itself have been identified in scientific literature at typical usage levels.

Regulatory Status

Metatartaric acid (E353) is approved for use as a food additive in the European Union (EU) and is listed in Annex II of Regulation (EC) No 1333/2008. It is also permitted for use in wine production in many other countries, subject to local regulations. The additive must meet specific purity criteria as defined by regulations to ensure its safety and quality. In the United States, metatartaric acid is generally recognized as safe (GRAS) for use in wine under specific conditions.