Effect of food emulsifiers on crystal structure and habit of stearic acid

Several food emulsifiers have been found to serve as crystal structure modifiers for stearic acid crystallized from various organic solvents. Stearic acid that usually precipitates under appropriate crystallization conditions as the B- form is converted into the C- form when 1- 5% of sorbitan esters or ethoxylated sorbitan esters of fatty acids are present in the solution. Other emulsifiers such as polyglycerol esters, bdsubstituted monoglycerides and sucrose esters of fatty acids consisting of bulky hydrophilic groups are also effective emulsifiers in preserving the C- form of the crystallized stearic acid. The active emulsifiers modify the external crystal habit of stearic acid. Mass spectrograph analysis indicates that sorbitan monostearate (Span 60) is precipitated with the stearic acid.