First discovered by Scheele (1789) from sour milk. Later Pasteur (1857) identified the MO involved in the lactic acid production.
In the Year 1881, first commercial production was started by Cointon processing Company, Iowa based on fermentation process.
Lactic acid is commercially produced by the synthetic method and as well as fermentation process.
Lactic acid is largely used in pharma and some plastic industries.
- Good solvent properties.
- Provides acidity in foods and beverages and served as preservatives in food stuff.
- Textile and laundry use lactic acid in fabric treatment.
- Calcium lactate is employed in baking powder and as a source of calcium in pharma industries.
- The pure form of lactic acid is used in plastic industry.
Carbon source :
glucose, maltose, sucrose or lactose
Crude substrate such as corn starch, potato starch, rice starch, lolassed have been used to supply carbon in the production medium.
Pre-treatment to starchy materials by enzyme or acid is necessary to bring about hydrolysis to maltose and glucose.
The sugar concentration in the production medium is initially adjusted to 5-20%.
Ammonium salts have been used. For eg. Ammonium hydrogen phosphate in the concentration of 0.25% is used (USA).
Growth factors and mineral source:
Those may be supplied by enriching the medium with crude vegetable sources.
pH : 5.5 -6.5
45-50o C for L. bulgaricus
30o C for L. casei, L. pentosus
A major problem in lactic acid production is that of product recovery and not of fermentation.
The method to be employed for recovery depends on the type of grade required.
There are different tuypes of grades needed for different purposes. Viz.
- Food grade
- Technical grade
- Plastic grade