| Odor | Practically odorless. Clean acidulous taste, resembling that ofCitric acid, but somewhat milder. |
| Chemical Properties | Erythorbic acid occurs as a white or slightly yellow-colored crystalsor powder. It gradually darkens in color upon exposure to light. |
| Uses | Antioxidant (industrial and food), especially inbrewing industry, reducing agent in photography. |
| Uses | Erythorbic Acid is a food preservative that is a strong reducing agent (oxygen accepting) which functions similarly to antioxidants. In the dry crystalline state it is nonreactive, but in water solutions it reacts readily with atmospheric oxygen and other oxidizing agents, making it valuable as an antioxidant. During preparation, dissolving and mixing should incorporate a minimum amount of air, and storage should be at cool temperatures. It has a solubility of 43 g/100 ml of water at 25°c. One part is equivalent to one part ascorbic acid and equivalent to one part sodium erythorbate. It is used to control oxidative color and flavor deterioration in fruits at 150–200 ppm. It is used in meat curing to speed and control the nitrite curing reaction and prolong the color of cured meat at levels of 0.05%. |
| Uses | Erythorbic Acid is used as a food additive as an antimicrobial and antioxidative agent. |
| Definition | ChEBI: D-isoascorbic acid is an ascorbic acid. |
| Production Methods | Erythorbic acid is synthesized by the reaction between methyl 2-keto-D-gluconate and sodium methoxide. It can also be synthesizedfrom sucrose, and produced from Penicillium spp. |
| Biotechnological Production | Yeasts and other fungi synthesize the C5 sugar acid D-erythroascorbic acid whichshares structural and physicochemical properties with Asc. D-erythroascorbicacid serves similar protective functions in these microorganisms as Asc does in plantsand animals, including the scavenging of reactive oxygen species. The biosynthesisof D-erythroascorbic acid starts from D-arabinose obtained by the microorganismfrom decaying plant material. D-arabinose, presumably in its1,4-furanosidic isomeric form, is oxidized by NAD(P)+ specific dehydrogenasesto D-arabinono-1,4-lactone, which is further oxidized to D-erythroascorbicacid by D-arabinono-1,4-lactone oxidase. Resting cells of Saccharomycescerevisiae can synthesize Asc from L-galactose, L-galactono-1,4-lactone, or L-gulono-1,4-lactone via the pathway naturally used for D-erythroascorbic acid. |
| Flammability and Explosibility | Non flammable |
| Pharmaceutical Applications | Erythorbic acid is a stereoisomer of L-ascorbic acid, and is used asan antioxidant in foods and oral pharmaceutical formulations. Ithas approximately 5% of the vitamin C activity of L-ascorbic acid. |
| Safety | Erythorbic acid is widely used in food applications as anantioxidant. It is also used in oral pharmaceutical applications asan antioxidant. Erythorbic acid is generally regarded as nontoxicand nonirritant when used as an excipient. Erythorbic acid is readilymetabolized and does not affect the urinary excretion of ascorbicacid.
The WHO has set an acceptable daily intake of erythorbic acidand its sodium salt in foods at up to 5 mg/kg body-weight. |
| Solubility in organics | 40% soluble in water. Soluble in alcohol, slightly soluble in Glycerin and Propyleneglycol. |
| storage | Erythorbic acid should be stored in an airtight container, protectedfrom light, in a cool, dry place. |
| Purification Methods | Crystallise D(-)-isoascorbic acid from H2O, EtOH or dioxane. is at 245nm with 7,500 (EtOH). [Reichstein et al. Helv max Chim Acta 17 510, 516 1934, Heslop et al. J Chem Soc 225 1944, Beilstein 18 III/IV 3037, 18/5 V 26.] |
| Incompatibilities | Erythorbic acid is incompatible with chemically active metals suchas aluminum, copper, magnesium, and zinc. It is also incompatiblewith strong bases and strong oxidizing agents. |
| Regulatory Status | GRAS listed. Accepted for use as a food additive in Europe.Included in the FDA Inactive Ingredients Database (oral concentrateand tablets). |
