2-Hydroxypropanoic acid or, as we call it, lactic acid, is a chemical compound formed from the breakdown of glucose and glycogen in the human body, but also across nature.
When the body produces lactic acid it splits into a lactate ion (lactate) and a hydrogen ion. The hydrogen ion (H+) is the ‘acid’ part and is readily neutralized in the body fluids; the lactate ion is a vital and essential fuel for the body.
Lactic acid was discovered by the Swedish chemist Carl Wilhelm Scheele in 1780 and first produced commercially by Charles E. Avery at Littleton, Massachusetts, in 1881.
Lactic acid provides a unique balance between acidic and antimicrobial properties. The acidity is a valued taste ingredient; and the antimicrobial functionality provides preservation and food safety. In a household cleaning product the acidity removes scaling while the antimicrobial functionality features as a disinfectant.
Lactic acid bacteria have been used by people to ferment or culture foods for preservation for at least 4000 years; mainly in fermented milk products like yoghurt, cheese, butter, kefir, and koumiss.
Besides being generally colorless and odorless, lactic acid has a recognizable but pleasant taste – especially found in sauerkraut and certain cheeses and yoghurts.
There are two types of lactic acid: L(+)-lactic acid and D(-)-lactic acid. The two types are each other’s mirror images, with different application potential. The L(+) form is found in the human body and formed or applied in many foods; while D(-)-lactic acid has more chemical uses, for instance in crop protection. Corbion manufactures both.
Some 95% of commercial lactic acid is produced through microbial fermentation (conversion without air) of carbohydrates: At Corbion this process has been developed over decades to deliver extreme purity.
The high purity of lactic acid is an absolute necessity in critical applications. In the pharmaceutical industry, for example, it’s used in parenteral and dialysis solutions in hospitals. Here sodium lactate, the salts of lactic acid, is acting as an electrolyte in the human body.
The high purity of lactic acid is also essential for the production of poly lactic acid (PLA) – which is one of the most widely used bioplastics in the world based on volume and number of applications. In making PLA, the alcohol group of one lactic acid molecule binds to the acid side of the next molecule, which creates long chains that forms the plastic.