mal·ic acid 
(mălĭk, mālĭk)
(mălĭk, mālĭk)n.
A colorless, crystalline compound, C4H6O5, used as a flavoring in foods and beverages. The levorotary form occurs naturally in wine and in many fruits, including apples, cherries, and tomatoes.
[French (acide) malique, from Latin mālum, apple, from Greek mēlon, mālon.]