Question

What is the purpose of using sodium lactate in soap?

Answer 1

The sodium salt of lactic acid is known as sodium lactate and its molecular formula is $Na{C_3}{H_5}{O_3}$. It is produced by the fermentation process of a sugar source like corn or beets followed by the neutralization process to form lactic acid. Sodium lactate has a wide range of applications in medicinal as well as the food sector.

Complete answer:
The structural formula of sodium lactate is represented as follows:

The various applications of sodium lactate are discussed below:
1. It acts as a preservative, acidity regulator and bulking reagent in various food products.
2. It is an effective moisturizer and humectant, therefore widely used in products like shampoo and liquid soaps.
3. It is used in soap solutions in order to speed up the unmoulding time and to produce harder and long-lasting bars of cold process soap.
4. It is also used to replace body fluids and minerals which are lost due to medicinal reasons. Due to its basic nature, it is widely used for medicinal purposes when the amount of acid increases in the blood.
Therefore, the use of sodium lactate in soap is for hardening and moisturizing purposes.

Note:
It is important to note that sodium lactate is not chemically similar to lactose as sodium lactate is just a salt of lactic acid whereas lactose is a protein milk specifically a disaccharide composed of galactose and glucose with molecular formula ${C_{12}}{H_{22}}{O_{11}}$. Hence, people suffering from lactose intolerance need not restrict themselves from sodium lactate.