11. Hibiscus tea contains 15-30 % organic acids, including citric acid, malic acid , and tartaric acid. 12. Most species of portulaca have mucilaginous, often acidic ( malic acid ) stems and foliage. 13. Tartaric acid is most often added, but winemakers will sometimes add citric or malic acid . 14. To achieve this they synthesize malic acid in the leaves from neutral precursors like carbohydrates. 15. For example, lactose, malic acid and testosterone which are formed only by carbon, hydrogen and oxygen. 16. Most commercial malic acid additives are a mixture of the enantiomers D + and L-malic acid. 17. Malic acid has two stereoisomeric forms ( L-and D-enantiomers ), though only the L-isomer exists naturally.18. Most commercial malic acid additives are a mixture of the enantiomers D + and L-malic acid . 19. As an example, malic acid has 4 carbon atoms but just one of them is asymmetric. 20. Malic acid occurs naturally in all fruits and many vegetables, and is generated in fruit metabolism.
