What is Butyric Acid? Structure, Properties, Uses

Butyric Acid

Butyric acid is a carboxylic acid with the structural formula CH₃CH₂CH₂-COOH. Butyrates are the name for butyric acid salts and esters. It smells bad, tastes bitter, and leaves a sweet aftertaste similar to ether. The acid is a colorless, oily solvent that can be saturated with salts like calcium chloride to distinguish it from an aqueous medium. It is miscible in water solution, ethanol, and ether. It may be oxidized by potassium dichromate, sulfuric acid, and alkaline potassium permanganate to produce carbon dioxide and acetic acid.

This article will discuss what butyric acid is, physical properties, structure and uses.

What is Butyric Acid?

With a 4-carbon structure, butyric acid is a saturated short-chain fatty acid. Natural fats and vegetable fats typically include butyric acid in their esterified form. Butyric acid has the formula C₄H₈O₂. The French chemist Michel Eugène Chevreul discovered this acid in 1818. It is also known as butanoic acid, which translates to “butter acid” because it was initially identified in stale butter. It is made by oxidizing n-butyl alcohol and fermenting starches.

Structure of Butyric Acid

Butyric acid, also known as butanoic acid, has the formula CH₃CH₂CH₂COOH, where the functional group connected is -COOH.

Butter makes about 3%–4% of butyric acid. Butter releases its rancidity when glycerol is hydrolyzed. A typical carboxylic acid like butanoic acid often interacts with bases and targets different metals.

Butyric acid smells bad and has a buttery flavor. Canines and other mammals can recognize this at 10 ppb. Humans, in contrast, can only sense this acid at levels more than 10 ppm.

Physical Properties of Butyric Acid

The following are the important physical properties of Butyric acid:

• Butyric acid, also known as Butanoic acid is an oily, colorless liquid with a foul smell.
• Butyric acid’s formula is C₄H₈O₂.
• This acid is soluble in water, ether and ethanol.
• It melts at 437 Kelvin.
• The boiling point of Butyric acid is 268 Kelvin.
• It has a liquid density of 1.135 g/cm3.

Chemical Properties of Butyric Acid

When butyric acid interacts with sodium hydroxide, it creates the sodium salt of butanoic acid, which also contains water and carbon dioxide

20NaOH + 21C₄H₈O₂ → 20 NaC₄H₆O + 4CO₂ + 34H₂O

After the acid is treated with water, ether and acetic acid are produced. The following is the chemical formula for this.

H₂O + C₄H₈O₂ → CH₃COOH + C₂H₆O

Production of Butyric Acid

Although the acid is not extensively distributed in nature, its esters are. It is a typical commercial chemical and a crucial part of the mammalian gastrointestinal system. It may be found in cow, human milk, dairy products like milk and cheese, body odor, plant and animal fats, and a byproduct of anaerobic fermentation. It is also found in the colon.

Industrial Production

In the industrial setting, butyric acid is made from propene and syngas by hydroformylation, resulting in butyraldehyde, which is then oxidized to the finished product.

H₂ + CO + CH₃CH=CH₂ → CH₃CH₂CH₂CHO → butyric acid

It may be removed from aqueous solutions by saturating it with salts like calcium chloride. Compared to cold water, the calcium salt, Ca(C₄H₇O₂)2H₂O, is not easily dissolvable in hot water.

Synthesis by Microbes

Numerous fermentation processes carried out by necessary anaerobic bacteria result in the production of butyrate. Louis Pasteur made this fermentation route public in 1861. Examples of bacteria types that produce butyrate include:

• Clostridium butyricum
• Eubacterium limosum
• Clostridium kluyveri
• Faecalibacterium prausnitzii
• Clostridium pasteurianum
• Butyrivibrio fibrisolvens
• Fusobacterium nucleatum

As in many species, the glycolytic breakdown of glucose into two pyruvate molecules initiates the route. Acetyl coenzyme A is produced by oxidizing pyruvate. As byproducts, two molecules of hydrogen (H₂) and two molecules of carbon dioxide (CO₂) are produced. The last stage of the fermentation then results in the production of ATP. For every molecule of glucose, three molecules of ATP are created, which is a comparatively high yield. The fermentation’s adjusted chemical equation is:

C₆H₁₂O₆ → C₄H₈O₂ + 2 CO₂ + 2 H₂

Uses of Butyric Acid

• Numerous crucial uses for butyric acid may be found in the chemical, food, and medicinal sectors.
• The chemical industry uses butyric acid extensively to create thermoplastics such as cellulose acetate butyrate.
• Other esters, such as glycerol tributyrate, are crucial in creating plastics.
• Butyric acid gives buttery overtones to food tastes, and its esters are frequently used as food preservatives to boost fruit aroma.
• Butyric acid, a type of short-chain fatty acid produced by microbial degradation of food fibers in the colon, is a primary generator of energy for the human body and a known colorectal cancer inhibitor.
• Its biological properties, which include therapeutic benefits for gastrointestinal disorders and cancer, have been extensively researched.

What is Butyric Acid’s Use in Different Industries?

Chemical Industry

• The principal usage of butyric acid is as a source in the synthesis of the copolymer cellulose acetate butyrate (CAB), which exhibits good performance with regards to organic solvent dissolution thanks to improved flexibility and resilience to light and cold.
• For improved heat and light tolerance, butyric acid can be added directly to plastic products and textile fibers.
• Butanol synthesis as a biofuel can also be improved by using butyric acid.

Perfume Industry

• Esters of butyric acid, including methyl, ethyl, and amyl butyrate, are utilized as aromatic compounds for perfume manufacture and as additions to improve fruit scent.
• It helps keeps the electrolyte balance in fragrances and acts as a bactericide.

Medicinal Purposes

• Butyrate protects the cells from harmful chemicals to maintain a healthy, disease-free stomach. The colon serves as a repository for waste materials. Increased antioxidant levels caused by butyrate have been found to reduce the risk of inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS).
• Since it inhibits the development of colorectal tumor cells, research has shown that butyric acid can both prevent and cure colon cancer.
• It can also be used in anti anxiety medication.

Animal Industry

• As an agent in the animal feed field, it provides energy and promotes sodium and water absorption.
• It maintains the gastrointestinal health of the animal and prevents diseases.
• Butyric acid promotes the proliferation of the epithelium.

Butyric Acid Safety Information

Butyric acid is a component in human excreta, skin, breath, and spit and is essential to functioning human metabolism. It is a normal occurrence in all dairy products, such as butter. Corrosion can occur when liquid butyric acid comes into contact with the skin or eyes. It is a combustible liquid that may seriously burn your skin and harm your eyes. Additionally, it has long-lasting negative impacts on aquatic life.

Precautions to be taken are:

• To prevent issues, read the label carefully before using it.
• Avoid inhaling the gas’s particles, mists, or vapors.
• After handling, properly wash your skin.
• Put on the appropriate eye and face masks, gloves, and clothes.
• Due to its extreme combustibility, maintain butyric acid away from fires and sources of heat.
• Refrain from releasing acid into the atmosphere.

In case of accidental contact:

• Eye contact: If the acid accidentally comes into touch with your eyes, immediately flush them out with lots of water for at least 30 minutes while elevating both your top and lower eyelids. If wearing contacts, take them out. Immediately contact a physician.
• Skin contact: Quickly take off any contaminated clothes after skin contact. Wash the skin with plenty of water right away.
• Inhalation: Remove the individual from the exposure if they inhale. Start CPR if the heart has stopped beating and rescue breathing if the breathing has ceased.

Conclusion

One of the healthiest short-chain fatty acids, butyric acid is essential for improving digestive health, reducing inflammation, protecting the brain, controlling weight, and preventing cancer. The body’s intestinal bacteria convert meals you can’t absorb into butyrate, which has various positive health effects. Adding more fiber to your meals can encourage your intestinal flora to produce more butyric acid.

The chemical, agricultural, medical, perfume, and animal feed sectors all use butyric acid and its compounds extensively. Although butyric acid alone smells bad, it is frequently employed as a pure acid to amplify aromas that resemble butter in flavors.

Frequently Asked Questions about Butyric Acid

Q1. What foods are a source of butanoic acid?

Answer: The following foods contain butanoic acid:

• Butanoic acid is present in ghee, oil, and butter at 3–4%.
• Dairy foods, including milk, cheese, and yogurt, frequently include it.
• Bananas, berries, grapes, avocados, apricots, and other fresh fruits that possess fiber are rich in them.
• It is also present in beans and lentils.

Q2. What is the process of preparing Butyric acid?

Answer: Butyraldehyde oxidation is used to produce butyric acid in large factories. It may be segregated from the water solution by saturation with salts like calcium chloride. The calcium salt, Ca(C₄H₇O₂)₂.H₂O, dissolves considerably slower in hot water than in the cold.

Q3. What type of compound is butyric acid?

Answer: With a 4-carbon structure, butyric acid is a short-chain saturated fatty acid. Animal fats and plant oils typically include butyric acid in its esterified form. Butane has had one of its distal methyl compounds converted to a carboxyl group, resulting in butyric acid, a straight-chain saturated fatty acid.