D-Malic AcidD-isomer of Malic Acid obtained Synthetically from fruits and vegetables and also known as synthetic malic acid (the exception being a few micro-organisms which produce D-malic acid). Freshly pressed fruit juices contain D-malic acid at the detection limit (~ 10 mg/L).
L-Malic AcidIn Nature, essentially all malic acid is produced in the L-Racemic form. It is found naturally in apple, grape’s pulp and other fruits and vegetables. It is also made by fumaric acid fermentation process. It is easily absorbed by human body, thus it is very important intermediate of human metabolism
D-malic acid is produced commercially in the D-/L-Racemic mixture by the catalytic hydration of maleic anhydride. DL- Malic acid is the racemic mix of D isomer and L isomer. Racemate can be made in the high temperature, high pressure conditions and water vapor effect by fumaric acid or maleic acid under the action of catalyst. DL-Malic Acid is now recognized as a safe food additive, sour agent, preservative and pH regulator, the acidity is soft and persistence, acidity is 20% stronger than citric acid .it can be used for all kinds of food, according to production need to use appropriately.