What Is The Importance Of Sodium Palmkernelate In Soap Making?

It is the active ingredient on some soaps.

First, a little chemistry.  Fats and oils, whether of animal or vegetable origin, are all poly esters of glycerol, a tribasic alcohol.  Each alcohol group has joined on to it a long chain carboxylic acid to form an ester linkage.  

Soaps are all made much the same way. The fat or oil is treated with concentrated sodium hydroxide (caustic soda) which causes hydrolysis of the ester groups in the fat or oil, splitting it up into glycerol and the sodium salt of the long chain carboxylic acid.  If the carboxylic acids are of lengths about 10 to 20 carbons long, then they are likely to be a soap.

Sodium palmkernelate is simply the soap made from palm oil.  Palm oil is unusual in that all three carboxylic acids are the same one, so ALL of the product of hydrolsis is a soap, and the same one. Hence a common con trick of advertisers of such soaps - "pure soap", meaning it is not a mixture like soaps made from animal fats. Not that that has any effect on its usefullness really. But sodium palmkernelate has about the right chain length to be a good soap.

Sodium Palm Kernelate is a salt of palm oil. This is obtained form the fruit of palm oil tree and can be used as vegetable oil. The kernelate is obtained by a process called saponification of oil.  It is found to be one of the ingredients of soap. You may notice this name on the soap wraps. Many brands use sodium palm kernelate as a basis for making soap. Dove and Palmolive are the leading brands.

This salt 'kernelate' is combined with other salts such as sodium tallowate. Even, salts of olive oils with kernelate could be used. These days the oils are made to react with lye (sodium hydroxide). The mass of saponified oil is left to harden or put in moulds. Kernelate is also used to make handmade or homemade soap.