FAT-CONTENT FOR NUTRITIONAL LABELING BY SUPERCRITICAL-FLUID EXTRACTION AND AN ONLINE LIPASE-CATALYZED REACTION

A method using sequential supercritical fluid extraction (SFE) and enz ymatic transesterification has been developed for the rapid determinat ion of total nutritional fat content in meat samples. SFE conditions o f 12.16 MPa and 50 degrees C were utilized to extract lipid species fr om the sample matrix. The enzymatic transesterification of the lipids by methanol was catalyzed by an immobilized lipase isolated from Candi da antarctica. Conversion of the triglycerides to fatty acid methyl es ters was monitored by supercritical fluid chromatography, while the fa tty acid content of the extract was determined by capillary gas chroma tography (GC). Total fat, saturated fat and monounsaturated fat conten ts were calculated from the GC data and compared to values from tradit ional extraction and lipid determination methods. Both off-line SFE an d automated SFE followed by on-line GC analysis using two different in struments were utilized in this study, The enzymatic-based SFE method gave comparable results to the organic solvent extraction-based method followed by conventional BF3-catalyzed esterification.