Supercritical fluid extraction and chromatography of emulsifiers

Selected emulsifiers, which included acetylated monoglycerides, lactylated monoglycerides, hexaglycerol distearate, triglycerol mono/dioleate and decaglycerol decaoleate, were separated with capillary supercritical fluid chromatography on a 25% cyanopropyl stationary phase with a mobile phase of CO₂ at 100–150°C. In general, the density/pressure programs that produced the best separations were those with reduced pressure/density ramp rates, which encompassed the largest possible pressure or density range. Samples of acetylated monoglycerides were placed in a supercritical fluid extraction cell on a glass bead bed and extracted for 15 min at 50°C at 340, 408, 544 and 680 atm with CO₂. At 544 atm, 103.6 ± 1.0% of the emulsifiers was extracted. Acetylated monoglycerides were added during twin-screw extrusion of cornstarch (3% w/w emulsifier/corn starch). The acetylated monoglycerides were extracted from the cornstarch extrudate for 15 and 45 min, at 544 and 646 atm and 50–120°C with 0 and 5% added methanol. The percent acetylated monoglyceride extracted after 45 min at 120°C and 646 atm was 60.0 ± 5.7%, while the amount extracted during a 7.5-h Soxtec extraction ranged from 17.9 to 29.4%, depending upon the solvent used.