Erythorbic acid
Other names: D-Araboascorbic acid, Erythorbate, Isoascorbic acid, E315
CAS number: [89-65-6]
Molecular formula: C6H8O6
Molar mass: 176.13 g/mol
Melting point: 169-172 deg. Centigrade

Erythorbic acid, formerly known as isoascorbic acid and D-araboascorbic acid, is a stereoisomer of ascorbic acid (vitamin C). It is a vegetable-derived food additive produced from sucrose. It is denoted by E number E315, and is widely used as an antioxidant in processed foods.
Clinical trials have been conducted to investigate aspects of the nutritional value of erythorbic acid. One such trial investigated the effects of erythorbic acid on vitamin C metabolism in young women; No effect on vitamin C uptake or clearance from the body was found. A later study found that erythorbic acid is a potent enhancer of nonheme-iron absorption
Technical Parameters (FCCIV)
Appearance: White or slightly yellow crystals or powder
Identification: Positive
Assay: 99.0~100.5%
Loss on drying: 0.4% max.
Specific Rotation: -16.5 deg. ~ -18.0 deg.
Residue on Ignition: 0.3% max.
Heavy metals: 10ppm max.
Lead: 5 ppm max.
Arsenic: 3ppm max.
Mercury: 1ppm max.
Oxalate: Pass the test
Packing: Net 25kg per paper carton or drum, with double PE inner bags