Differential scanning calorimetric studies on structured lipids from coconut oil triglycerides containing stearic acid

<p align="justify">Triglycerides from coconut oil contain high levels of lauric acid. They were replaced by incremental amounts of stearic acid by interesterification reactions catalyzed by immobilized lipase (IM 60 from Rhizomucor miehei). The reactions were carried out in organic solvents such as hexane. Maximum incorporation of
stearic acid was observed by 4 h at 37 7C or by 2 h at
60 7C when triglycerides to fatty acid (stearic acid) ratio
was maintained at 1: 6. The stearic acid level in coconut
oil triglycerides was increased from an initial value of
2% to 60% under these conditions. The stearic acid replaced
lauric, myristic, and palmitic acids in unmodified
triglycerides. A major portion of stearic acid incorporated
was found in positions 1 and 3 of triglycerides.
Differential scanning calorimetry indicated that stearic
acid enrichment increased the solid fat content and also
the higher melting polymorphs in modified lipids. The
studies also indicated that low melting polymorphic
forms of coconut oil triglycerides are converted to higher
melting forms by stearic acid enrichment. The modified
lipids thus obtained can find use in various food applications.</p>