Fumaric acid is a dicarboxylic acid that has played an important role in both natural metabolism and industrial applications. Known for its crystalline appearance and distinct tartness, it is not just a laboratory chemical but a compound with a long history of use in food preservation, pharmaceuticals, agriculture, and polymer chemistry. Found naturally in many plants, lichen, and fungi, fumaric acid is also a critical intermediate in the tricarboxylic acid (TCA) cycle, one of the most important metabolic pathways in living organisms.
Today, fumaric acid has transitioned into an industrially significant compound, produced at scale and utilized across multiple sectors. From regulating the acidity of fruit juices to treating autoimmune diseases through derivatives like dimethyl fumarate, its versatility cannot be overstated.
Structure & Properties
Fumaric acid is the trans isomer of butenedioic acid, distinguishing it from the cis isomer, maleic acid. The trans configuration grants it greater stability and higher melting point (~287 °C) compared to maleic acid’s ~139 °C. Its molecular formula is HOOC–CH=CH–COOH, and it appears as a white crystalline powder or monoclinic prism, sometimes with a fruity odor
Physical & Chemical Properties
| Property | Value |
| Molecular Weight | ~116.07 g/mol |
| Melting Point | ~287 °C (decomposes) |
| Solubility | Sparingly soluble in cold water; better in hot water and alcohol |
| pKa₁ / pKa₂ | ~3.03 / ~4.44 |
| Density | ~1.635 g/cm³ |
| Stability | Thermally stable; low hygroscopicity |
Natural Occurrence and Biological Significance
Fumaric acid is not simply a synthetic chemical—it is deeply embedded in biological systems:
- Plants and Fungi: Found in lichen, mushrooms, and several plants where it contributes to sourness.
- Metabolism: Plays a central role in the Krebs (TCA) cycle, where fumarate is produced by oxidation of succinate and then hydrated to malate.
- Skin: Under UV exposure, human skin naturally produces fumaric acid derivatives, which have been linked to immune modulation.
- Historical Medicine: In folk remedies, fumaric acid-rich extracts from plants were used for skin conditions long before modern pharmacology.
Its biological presence laid the foundation for its pharmaceutical applications centuries later.
Production and Synthesis
Industrial fumaric acid is produced primarily through chemical isomerization and catalytic processes.
Main Methods
Isomerization of Maleic Acid/Anhydride
- Maleic acid, the cis-isomer, is converted to fumaric acid (trans-isomer) using heat, catalysts, or UV light.
- Maleic anhydride hydrolysis is another key precursor route.
Biotechnological Production
- Recent trends favor microbial fermentation using Rhizopus oryzae strains.
- Offers renewable, sustainable production compared to petrochemical routes.
Laboratory Methods
- Oxidation of furfural or resins.
- Oxidation of succinic acid derivatives.
Biotechnological methods are gaining importance due to global sustainability goals and demand for greener chemistry.
Chemical Reactions and Derivatives
Fumaric acid participates in multiple organic reactions that extend its utility.
- Esterification: With alcohols, forms esters like dimethyl fumarate (DMF) and diethyl fumarate—used in medicine and industry.
- Polymerization: Forms cross-linked resins in unsaturated polyester resin (UPR) production.
- Addition Reactions: Functions as a dienophile in essential Diels–Alder organic reactions.
- Salt Formation: Salts like sodium fumarate, calcium fumarate, and potassium fumarate find applications in food fortification and pharmaceuticals.
Key Derivative – Dimethyl Fumarate (DMF):
- FDA-approved medication treating psoriasis and multiple sclerosis.
- Works as an immunomodulator by affecting oxidative stress pathways.
Applications Across Industries
Fumaric acid’s applications are widespread, spanning food, pharmaceuticals, polymers, and agriculture.
Food & Beverage
- Acidulant: Regulates acidity in soft drinks, juices, and bakery.
- Preservative: Prolongs shelf life by preventing unwanted microbial activity.
- Flavor Enhancer: Enhances fruit flavors with a distinct, sharp sourness.
- Baking Industry: Reacts with baking soda to release CO₂.
- Non-hygroscopic Advantage: Stays stable in dry mixes unlike citric acid.
Pharmaceuticals & Medical
- Dimethyl fumarate (DMF):Approved treatment for both multiple sclerosis and psoriasis.
- Calcium fumarate: Nutritional supplement and calcium source.
- Potential in Oncology: Ongoing studies on fumarate derivatives in cancer pathways.
Industrial Uses
- Polyester Resins: Used in unsaturated polyester resin (UPR) for automotive and construction.
- Paper Sizing: Improves strength and durability of paper products.
- Plasticizers: Enhances flexibility in plastics.
- Toner Production: Component in certain printing toners.
Agriculture & Cosmetics
- Feed Additive: Improves animal growth and reduces methane emissions.
- Cosmetics: Mild acidulant for creams and gels.
- Biodegradable Inputs: Supports sustainable farming practices.
Applications Table
| Industry | Application Area | Benefits / Notes |
| Food & Beverage | Acidulant, preservative, baking | Stable, non-hygroscopic, long shelf life |
| Pharmaceuticals | Psoriasis & MS drugs, supplements | Immunomodulatory, nutritional enhancement |
| Industrial | Resins, toners, paper, plastics | Strength, durability, flexibility |
| Agriculture | Feed additive, soil enhancement | Growth boost, methane reduction |
| Cosmetics | Creams, gels, pH regulator | Safe acidulant, mild effect on skin |
Safety, Regulatory Status, and Toxicology
Fumaric acid is generally regarded as safe (GRAS) by multiple authorities.
Safety Assessments
- Acute Toxicity: LD₅₀ in rats ~10,000 mg/kg (low toxicity).
- Irritation: Generally non-irritant in low concentrations; high doses may cause GI discomfort.
- Medical Use Risks: Derivatives like DMF may cause flushing, nausea, or reduced white blood cells.
Regulatory Approvals
- FDA (USA): GRAS status for food use.
- EFSA (EU): No specified ADI (safe at typical levels)
- JECFA (WHO/FAO): Confirmed safety in human consumption.
- Pharmaceutical Approval: Dimethyl fumarate approved for MS treatment.
Overall, fumaric acid is safe in food and industrial use when applied within regulatory limits.
Market Outlook and Trends
Fumaric acid has experienced steady growth due to its versatility and safety profile.
Global Market Size: Estimated USD 700–750 million by 2027.
CAGR Growth: ~4–6% annually.
Driving Factors:
- Rising demand for food preservatives and acidulants.
- Expanding pharmaceutical applications (especially DMF).
- Growth in unsaturated polyester resin (UPR) market.
- Shift toward bio-based fumaric acid from fermentation.
Regional Insights:
- Asia-Pacific:Biggest market demand driven by China and India.
- Europe: Strong pharmaceutical applications (MS treatment drugs).
- North America: Balanced demand in food, pharma, and plastics.
Sustainability will define the future of fumaric acid production, with biotech fermentation likely to dominate in the next decade.
Fumaric acid is far more than a sour-tasting crystalline powder. It bridges the gap between biological metabolism and industrial chemistry, serving as a building block in food, pharmaceuticals, polymers, and environmental solutions.
Its GRAS status, versatility in derivatives, and role in modern medicine make it indispensable. With the added push toward green chemistry, biotechnological production methods are set to transform fumaric acid into a sustainable compound for the future.
For manufacturers and buyers alike, fumaric acid represents both a reliable traditional ingredient and a frontier of innovation. Its market growth, regulatory approvals, and broad industrial applications ensure that fumaric acid will continue to be a cornerstone chemical in global industries.