Solvent-free lipase-catalyzed preparation of diacylglycerols.

Various methods have been applied for the enzymatic preparation of diacylglycerols that are used as dietary oils for weight reduction in obesity and related disorders. Interesterification of rapeseed oil triacylglycerols with commercial preparations of monoacylglycerols, such as Monomuls 90-O18, Mulgaprime 90, and Nutrisoft 55, catalyzed by immobilized lipase from Rhizomucor miehei (Lipozyme RM IM) in vacuo at 60 degrees C led to extensive (from 60 to 75%) formation of diacylglycerols. Esterification of rapeseed oil fatty acids with Nutrisoft, catalyzed by Lipozyme RM in vacuo at 60 degrees C, also led to extensive (from 60 to 70%) formation of diacylglycerols.

Stereospecific incorporation of palmitoyl, oleoyl and linoleoyl moieties into adipose tissue triacylglycerols of rats results in constant sn-1:sn-2:sn-3 in rats fed rapeseed, olive, conventional or high oleic sunflower oils, but not in those fed coriander oil.

We report the stereospecific (sn-1, sn-2, sn-3) distribution of fatty acids in subcutaneous adipose tissue triacylglycerols of male weaned Wistar rats fed either a standard diet or diets containing, in addition to 20 g corn oil/kg feed, 120 g/kg feed, each, of canola-type rapeseed oil, olive oil, conventional or high oleic sunflower oil or high petroselinic coriander oil for 10 wk. The regiospecific distribution of the major acyl moieties in the sn-1 (3) vs. sn-2 positions of the adipose tissue triacylglycerols broadly reflected that of the dietary oils.

The composition of the major molecular species of adipose tissue triacylglycerols of rats reflects those of dietary rapeseed, olive and sunflower oils.

We report the composition of constituent fatty acids and molecular species of adipose tissue triacylglycerols of male weaned Wistar rats fed diets containing, in addition to 20 g corn oil/kg feed, 120 g per kg feed canola-type rapeseed oil, olive oil or conventional sunflower oil for 10 wk. The composition of fatty acids and molecular species of the triacylglycerols of subcutaneous, epididymal and perirenal adipose tissues did not differ among groups (P > 0.01), broadly reflecting the corresponding compositions of the dietary oils.