Color and odorless, related to the sugars and strongly acidic crystalline acid, their salts are called ascorbates. The name derives from the Greek "a" (for "not") and the vitamin C deficiency scurvy (meaning "you do not get scurvy"). Of the four existing forms, only L-ascorbic acid is biologically active, and also its derivatives under the name vitamin C be summarized. It is present in many fruits and vegetables, for example in bush plum (3,150 mg in 100 g), acerola cherry (1,700), rosehip (1,250), blackcurrant (180), kale (150), broccoli (115) and lemon (53) available. In plant metabolism she plays in the photosynthesis an important role. Also in the green grapes it occurs during maturity and winemaking but the proportion goes back to zero.
Ascorbic acid is extracted industrially glucose produced. As it is easily oxidized, it is used as a preservative or antioxidant. As Oxidation inhibitors she is especially in the New world used. Already the grapes are sprayed after reading. It may be added to wine up to a maximum of 150 mg / l. This is often done together with sulfur dioxide but is not a substitute. Ascorbic acid is about to bottling especially white wine mixed. The oxygen in the wine is absorbed, thereby oxidizing ascorbic to dehydro-ascorbic acid. The wines stay fresh longer. Rather negative is the addition of heavy white wines and aging red wines. The proportion in the wine is with chromatography or iodometry determined and expressed in mg / l. See also below Means in winemaking,