Acidity is the level of acids in fruits. Many fruits contain acids of which malic acid and citric acid are the most common ( citrus fruits, beetroot, pumpkin, cucumber ). Oxalic acid is present in many foods, particularly in green leafty vegetables ( spinach, amaranth ), in certain fruits ( green plantain, AMLA, PHALSA ) and in some vegetables ( drumstick, lotus stem, plantain flower ). Tartaric acid occurs in certain fruits ( grapes, tamarind pulp ), and succinic and benzoic acids are also sometimes present.