Sodium benzoate glycine "N"-acyltransferase into hippuric acid. In combination with ascorbic acid (vitamin C, E300), sodium benzoate and potassium benzoate may form benzene. When tested by the FDA, most beverages that contained both ascorbic acid and benzoate had benzene levels that were below those considered dangerous for consumption by the World Health Organization (5 ppb). Most of the beverages that tested higher have been reformulated and subsequently tested below the safety limit. Heat, light and shelf life can increase the rate at which benzene is formed. Research published in 2007 for the UK's Food Standards Agency (FSA) suggests that certain artificial colors,
Chemistry of ascorbic acid catalytically hydrogenated to sorbitol, which is then oxidized by the microorganism "Acetobacter suboxydans" to sorbose. Only one of the six hydroxy groups is oxidized by this enzymatic reaction. From this point, two routes are available. Treatment of the product with acetone in the presence of an acid catalyst converts four of the remaining hydroxyl groups to acetals. The unprotected hydroxyl group is oxidized to the carboxylic acid by reaction with the catalytic oxidant TEMPO (regenerated by sodium hypochlorite — bleaching solution). Historically, industrial preparation via the Reichstein process used potassium permanganate as the bleaching solution. Acid-catalyzed hydrolysis of this product