Distilled fatty acids from Egyptian waste soapstock were blended with
cottonseed or olive oils and interesterified via pancreatic lipase. Th
e reaction was conducted at 55 degrees C for 10 h to reach equilibrium
at which point 45% interesterification was accomplished. The specific
ity of 1,3 lipase was apparently reduced by the acid environment of th
e interesterification reaction. Acyl migration was observed among all
the carbons of the glycerol moiety of the interesterified triacylglyce
rol products. Differential scanning calorimetry was used to evaluate c
hanges in melting and crystallizing properties of vegetable oil-soapst
ock fatty acid blends before and after enzymic interesterification. Me
lting and crystallizing temperatures of the interesterified blends wer
e significantly lowered.