Propionic acid (E280), also known as propanoic acid, is a type of carboxylic acid. It is an organic compound that has the ability to react with other chemicals, and can therefore be used as a food additive to improve bland or unpleasant tastes. Propionic acid has many different uses, ranging from food and medicine to cosmetics and even insecticides.
Which is propionic acid?
Propionic acid also called propanoic acid and methyl propanoate is a carboxylic acid with the molecular formula CH3CH2CO2H. It is a colorless liquid with a pungent odor. Propionic acid is miscible with water, ethanol, and ether.
It is produced naturally in fermented products such as cheese, yogurt, buttermilk, and bread; it can also be synthesized in the laboratory under special conditions. It has a wide range of applications including use as a food additive, chemical intermediate, and pharmaceuticals production.
Propionic acid was discovered by Justus von Liebig in 1835 by treating silver carbonate with ethyl alcohol (ethanol) overheat to produce ethyl acetate:
What is propionic acid used for?
Propionic acid is a carboxylic acid. It’s a white crystalline solid that’s soluble in water and alcohol.
Propionic acid is used to make other chemicals and as a preservative in food. It’s also used in the production of polypropylene (a type of plastic) and acrylates (chemicals used to make plastic products).
Propionic acid can be used topically to treat fungal infections, such as athlete’s foot or jock itch. It can also be taken by mouth to treat fungal infections of the vagina or penis, but it may cause nausea and vomiting.
In animals, propionic acid is an important intermediate in the metabolism of carbohydrates and fats. In humans, it occurs naturally in small amounts in dairy products and other foods.
What is propionic acid made from?
Propionic acid is a fatty acid with the molecular formula CH3CH2COOH. It is a constituent of some short-chain fatty acids, propionate and ethyl propionate, which are produced by fermentation processes. Propionic acid is also produced naturally in the body as a product of carbohydrate metabolism.
The compound may be prepared in large quantities by carbonylation of acetylene using concentrated sulfuric acid as a catalyst at 400-600 °C. The process was first described in Germany during World War II by Günther Wampfler.
The reaction produces an excess of carbon monoxide, which is removed by the water gas shift reaction to form hydrogen and carbon dioxide. This method is still used today on an industrial scale, although it has been superseded by more efficient processes such as the oxidation of methanol over copper catalysts.
How is propionic acid made?
In addition to chemical synthesis, propionic acid can also be produced by bacterial fermentation. There are five main manufacturing processes, where petrochemical processes dominate mainstream industrial synthesis.
- It is synthesized from ethylene (petroleum-based), carbon monoxide, and steam. Here is the flow chart:
- A mixture of carbon monoxide and hydrogen is reacted with ethylene to produce propionaldehyde, and propionaldehyde is oxidized. This is the reaction equation:
- Using boron trifluoride as a catalyst, ethanol is reacted with carbon monoxide.
- Biosynthesis with propionibacterium, but there is still a long way to go before this method is large-scaled and commercially available.
- Byproduct of wood pyrolysis.
How does propionic acid work as a preservative?
Propionic acid preserves similarly to benzoic acid and sorbic acid. pH ranges between 2.5 and 5.5 are optimal for its antimicrobial effectiveness.
It is the undissociated form of propionic acid that has antimicrobial properties. Propionic acid penetrates the membrane of microbial cells and enters the cytoplasm.
As propionic acid accumulates and dissociates, it lowers the internal pH of the microbial, preventing it from growing or even killing it.
Specification
| Other names |
|
| Chemical formula | CH3CH2COOH, C2H5COOH, C3O2H6 |
| CAS Number | 79-09-4 |
| Molecular weight | 74.08 |
| Boiling Point | 141 °C |
| Melting point | -22.4 ºC |
Properties
This is a volatile acid. It is an oily liquid with a slightly pungent and rancid odor, unlike its salts potassium, calcium propionate and sodium propionate
Propionic Acid Structure
Functional group
- As a result of esterification, internal esterification, amine reaction, and substitution reaction, the carboxylic acid can produce the derivatives of ester, anhydride, amide, and chloride.
- Using bromine, the carboxylic acid can undergo alpha-c halogenation.
Solubility
- In water: soluble in water.
- In organic solvents: soluble in ethanol and most organic solvents.
PH
Propanoic acid reacts with water to form H3O+ and CH3CH2COO- (conjugate bases). With a PKa value of 4.88, it is less acidic than sorbic acid and benzoic acid.
In water, the dissociation equation is as follows.
H3CCH2CO2H(aq) +H2O(l)⇌H3CCH2CO−2+H3O+
A concentration of 1nmol/L results in a PH value of 3.96.
What’s the application of propionic acid?
Typically, propionic acid is used to inhibit mold growth in food and feed. Moreover, due to the presence of carboxylic acid and alpha-c of carboxylic acid in the molecule, it can be converted into various derivatives with a wide range of applications in dyes, textiles, plastics, pesticides, perfumes, cosmetics, and pharmaceuticals. In 2019, China exported around 7,200 MT for 9 million dollars.
Food
Mold inhibitors, such as propionic acid, are fungistatic, not fungicidal. A concentration of 0.05 to 0.25% is effective against molds. It is less effective at inhibiting the growth of bacteria and has no effect on the growth of yeast.
Propionic acid can be used as a preservative in the following foods when combined with its salts, sodium propionate and calcium propionate:
- Bread
- Tortillas
- Cheeses
- Cakes
In addition, it is a raw material for the manufacture of vitamin E.
Animal Feed
Due to its less corrosive nature than propionic acid, ammonium propionate on the market is mainly used as a preservative in animal feed and grain.
Here are some feeds that may contain it:
- Grains with high moisture content, such as oats, corn, and barley
- The hay
- Poultry and livestock drinking water
Propionic acid can be partially neutralized with ammonia or ammonium hydroxide to produce ammonium propionate, which is not a food additive.
Is propionic acid safe?
It has been approved as a safe ingredient by the FDA and the Europe Food Safety Authority (EFSA). Also WHO Expert Committee on Food Additives.
FDA
The use of propionic acid as an antimicrobial agent and flavoring agent in food is generally recognized as safe (GRAS) under current good manufacturing practices. The chemical preservative is also GRAS when used in feed as a preservative.
EFSA
According to Regulation (EU) No 231/2012, propionic acid (E280) is an authorized food additive listed under “Additives other than colors and sweeteners”.
Approved uses
A maximum permitted level (MPL) of 1000 to 3000 mg/kg in foods is listed with sodium propionate (E281), calcium propionate (E282), and potassium propionate (E283).
Safety re-evaluation in 2014
As a food additive, propionic acid is not considered genotoxic or carcinogenic by EFSA. The maximum permissible usage poses no safety concern. Due to the available toxicity database, no ADI was assigned.
UK Food Standards Agency
The item is categorized as “Others”
Food Standards Australia New Zealand
In Australia and New Zealand, it is approved under code number 280.
JECFA
Classification: food additives, flavoring agents, preservatives.
ADI “not limited” set in 1973.
What are the side effects of propionic acid?
Propionic acid is a fatty acid that occurs naturally in the body. It’s also used as a food additive and preservative, especially in baked goods.
Side effects of propionic acid include:
Mild to moderate irritation of the skin, eyes, nose, throat, and lungs. This is due to exposure to propionic acid vapors or dust.
Severe abdominal pain (with or without diarrhea) is associated with vitamin B12 deficiency. Propionic acid can interfere with the absorption of vitamin B12 from foods, leading to low levels of this important vitamin in your blood (pernicious anemia).
What does propionic acid do in the body?
Propionic acid is a short-chain fatty acid that is produced naturally by the human body and found in many foods, including cheese, yogurt, and other fermented products. Propionic acid is also used as a preservative in many foods, including meats and baked goods.
Propionic acid has several important functions in the body.
In the gut, propionic acid helps to maintain an acidic environment that prevents pathogenic bacteria from growing. Propionic acid may also play a role in helping to regulate blood sugar levels by encouraging the breakdown of fats into fatty acids which can be used as fuel for energy production. In addition, propionic acid may help to prevent or treat certain types of diarrhea caused by antibiotics or other medications (such as quinolone antibiotics).
Where to buy propionic acid?
The best place to buy propionic acid is from your local chemical supply company or other industrial chemicals supplier that will most likely carry 99%+ purity grade. If you have trouble finding it locally, try an online chemical supplier like Sigma Aldrich or Lancaster Scientific.
You also can buy propionic acid at Walmart and other stores. You can also find it on Amazon or eBay. if you buy a large quantity for your company or project, you can purchase it from Grade Chemical. they are one reliable propionic acid manufacturer in China.
Frequently Asked Questions
Is propionic acid natural?
Propionic acid is a natural chemical that is produced in the body. It’s also used as a preservative in many foods, including bread, cheese, and yogurt.
Is propionic acid vegan?
Yes, propionic acid is vegan. It’s made from the fermentation of carbohydrates and does not use any animal products in its production, so it’s safe to use for vegans.
Is propionic acid gluten free?
Yes, propionic acid is gluten-free. Propionic acid is a type of short-chain fatty acid that is naturally found in dairy products and animal feed. It can also be produced synthetically. It is used as a preservative and a flavoring agent in food products.
Is propionic acid acidic or basic?
Propionic acid is a carboxylic acid, meaning that it has a -COOH group attached to the carbon chain. The -COOH group is carboxylic, which means it has acidic properties.
Conclusion
In summary, propionic acid is a safe preservative commonly used in baked goods and other foods. It has no known health risks. When food products containing propionic acid reach the market, they have undergone the same rigorous review as their counterparts with no propionic acid.
If you have any questions about this additive, feel free to let us know in the below comments.
