Malic acid
General Product Information
| Article | Malic acid |
| Synonyms | E296, 2-Hydroxybutanedioic acid, Hydroxybutanedioic acid, 2-Hydroxysuccinic acid |
| CAS No. | 97-67-6 |
| EEG No. | – |
| EINECS No. | 202-601-5 |
| IMO | – |
| Tariff Code | 29181998 |
| UN No. | – |
| VLG/ADR | – |
Description
Malic acid is a naturally occurring organic acid that belongs to the group of hydroxycarboxylic acids. It occurs naturally in many fruits, especially apples, pears, berries and grapes. Chemically, it is a dicarboxylic acid with an asymmetric carbon atom, making it optically active. In its L form (naturally occurring), it is biologically active and plays an important role in the citric acid cycle (Krebs cycle), a fundamental metabolic process in living organisms. Malic acid is available as a white crystalline powder, soluble in water, with a distinctive fresh, sour taste.
Characteristics
- Source: Produced both naturally and synthetically.
- Odor: –
- Color: White to off-white.
- Grade: Food.
- Solubility: Highly soluble in water; limited in ethanol.
- Flavor: Fresh acidity.
- Shape: Crystalline powder.
Physical & Chemical Properties
| Chemical Structure | C4H6O5 |
| Molar Weight | 134.09 g/mol |
| Melting Point | 101-105 °C |
| Boiling Point | Approx. 150 °C. |
| Density | 1.595 g/cm³ at 20 °C |
| Refractive Index | – |
| pH | Approx. 2.2 (on 1% solution). |
Applications
Malic acid is applied in various ways, for instance:
1. Food Industry
Malic acid is approved as a food additive (E296) and is used as an acidity regulator, flavor enhancer and preservative. It is widely used in soft drinks, candy, fruit juices, wine, beer and sports foods.
2. Pharmaceutical Industry
Malic acid serves as an excipient at the formulation of oral medications to improve taste or increase solubility.
3. Technical Applications
Used as an intermediate in the synthesis of esters, in electroplating processes and as a pH buffer in laboratories.
4. Cosmetic Industry
In skin care, it is used as a pH regulator and as a mild exfoliating ingredient in chemical peeling products.
Interessing Links
- Codex Alimentarius (FAO/WHO) – Guidelines and standards for food additives and ingredients.
- European Chemicals Agency (ECHA) – For chemical information and regulations.
- European Food Information Council (EFIC)
- European Food Safety Authority (EFSA) – Information on the safety and uses of food additives and ingredients.
- PubChem – L-Malic Acid – Chemical information by the National Library of Medicine of the National Center for Biotechnology Information (NIH-NCBI).
- Wikipedia – Malic acid