Product that is naturally found in most fruits, especially citrus ones, and which is industrially produced through fermentation of sugar by the fungus Aspergillus niger. It is used in medical compounds as effervescent, to treat intestinal affections, as antioxidant, as an agent for alkalizing urine and dissolution of urinary tract stones. In the food industry it is used as additive (E 330) due to its antioxidant, preservative and flavoring properties. Devoid of toxicity when used at appropriate doses.