CHAPTER XI 



MISCELLANEOUS FERMENTATIONS, FAT-SPLITTING 

 ENZYMES, OXEDASES, CLOTTING ENZYMES 



Fat-Splitting Enzymes. It is a matter of common observa- 

 tion that household fat, if allowed to accumulate, becomes 

 what is termed rancid and evil smelling. This is due to 

 fermentation of the fat with production, amongst other 

 substances, of free fatty acids, which have an unpleasant smell. 



Fats are denned chemically as esters of the so-called fatty 

 acids with glycerine. Glycerine is an alcohol containing three 

 hydroxyl groups with the formula CH 2 OHCHOHCH 2 OH. 



Mutton or beef fat or stearin is a compound of glycerine 

 and stearic acid, the latter having the formula C^H^COOH. 

 Stearin therefore, being a glycerol ester of stearic acid, has 

 the formula C^C^CO^. 



Soap is formed by the decomposition of fats by means of 

 alkali, glycerine being obtained as a by-product, while the 

 soap is the alkali salt of the fatty acid. Thus, e.g., if stearin 

 is heated with caustic soda the following reaction takes place : 



C 17 H 35 C0 3 CH 2 C 17 H 35 C0 2 Na CH 2 OH 



I I 



C 17 H 35 C0 2 -CH+ 3NaOH = C 17 H 35 C0 2 Na + CHOH 



C 17 H 35 C0 2 -CH 2 C 17 H 35 C0 2 Na CH 2 OH 



Stearin Caustic Soda Sodium Stearate Glycerol 



(Soap) 



This process of splitting up of fat with formation of a soap 



