Vitamin C is white crystal or crystalline powder, odorless, sour, and the color will gradually turn yellow over time. Easily soluble in water and acid. Fresh vegetables and fruits. Tomatoes, broccoli, sweet peppers, dark leafy vegetables, bitter gourd, citrus, grapefruit, apples, grapes, kiwi fruit, fresh dates, etc. are rich in vitamin C.

Vitamin C and sodium carbonate can form monosodium salt without being hydrolyzed. The lactone ring becomes stable due to the double bond, but in a strong alkaline solution, the lactone ring can be hydrolyzed to form a keto acid salt.