Question: how uronic acid is formed?
Answer: 5.3 Uronic Acids Uronic acids are derived from the oxidation of the hydroxyl group on C6 of aldoses. The main uronic acids found in wines made from healthy grapes are d-galacturonic acid and d-glucuronic acid, whose concentrations range from 40 to 400 mg/L and from 0 to 60 mg/L, respectively.