citric acid dripping off of a lemon slice

5 Uses of Citric Acid

What is Citric Acid?

Citric is a weak organic acid with the chemical formula C6H807. Citric acid is a naturally occurring acid found in citrus fruits, tomatoes, and many other fruits and vegetables, and one of the large numbers of metabolites produced by Aspergillus species. In its natural form, it looks very similar to table salt (small, clear crystals), and although it is odorless, it has an acidic taste.

The History of Citric Acid

Citric acid was first isolated by Carl Wilhelm Scheele from lemon juice in 1784. During that time in history, chemists were avidly seeking the elements and chemistries that make up everything, along with their functions, by isolating different chemicals. (A large amount of citric acid (about 47g per liter) is contained in lemon juice and can be isolated by precipitation of calcium citrate using hydrated lime (calcium hydroxide) then acidified with diluted sulfuric acid).

In 1893, Carl Friedrich Wilhelm Wehmer discovered that penicillium mold could produce citric acid from sugar. This became the industrial method of citric acid production until 1917.

In 1917, food chemist James Currie discovered that any strain of the filamentous mold Aspergillus niger would produce high concentrations of citric acid when grown in sugar medium. The fungus Aspergillus niger is a type of mold which can sometimes be attributed to the cause of some cases of pneumonia as well as the causative agent of “black mold” on the outer surface of certain foods such as apricots, onions, grapes, etc. when the food is spoiled.

With WWI (1914-1918) came a shortage of citrus (Italian citrus exports), which made the fermentation method much more industrially important. Two years after Currie’s discovery, industrial-level production using Aspergillus niger started, the biochemical fermentation industry began to flourish, and industrial biotechnology was born. A century later, citric acid production using Aspergillus niger is a multi-billion-dollar industry, with this mold additionally producing a diverse range of proteins, enzymes, and secondary metabolites.

5 Uses of Citric Acid

1. Citric Acid is an Efficient Chelator

Citric acid is a triprotic acid (it can donate 3 hydrogen atoms per molecule in a reaction) making it a great chelator (chelation is a type of bonding of ions and molecules to metal ions). It binds metals by making them soluble which is very useful to remove and prevent calcium buildup when using hard water. EDTA is the most common chelator but citric acid is a natural and renewable resource.

2. Citric Acid as a Cleaning Agent

By breaking down trace amounts of metal found in hard water, citric acid is an ingredient in various household cleaners to assist in cleaning hard water stains. This is a natural alternative to harsh, industrial chemical cleansers.

3. Citric Acid as a Water Softener

Because citric acid is an organic acid, an effective chelator, and has buffering qualities, it is used as a water softener in detergents. Citric acid makes a strong water softener due to its chemical properties as a weak organic acid. Citric acid is preferable to polyphosphates that are commonly used as an industrial water conditioner. But high levels of phosphorous can cause algae blooms which can be harmful to human and aquatic life.

4. Citric Acid in Cosmetics

Citric acid is utilized in many ways in the cosmetics industry. It has a buffering capacity which is used to adjust the pH of skincare products. It has anti-aging properties because it is a natural antioxidant. Citric acid is an Alpha-hydroxy acid, meaning it acts as a gentle and natural exfoliant that can help treat acne, reduce dark spots, improve skin texture, and smooth fine lines and wrinkles.

5. Industrial Uses of Citric Acid

Citric acid is used in such industries as detergent manufacturing, electroplating, leather tanning, as a preservative for stored blood, and as a buffer and antioxidant in the pharmaceutical industry. In addition, several citric acid fungal-derived acids have significant commercial value and have found wide-ranging applications in the food, feed, pharmaceutical, and polymer industries.

Get a Quote for Citric Acid

Noah Chemicals will work with you to meet your citric acid needs in multiple industries. For more information about how Noah Chemicals can assist you with the highest quality citric acid, please request a quote or call (888) 291-1186.

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