The application of ultrasound energy to increase lipid extraction throughput of solid matrix samples (flaxseed).Prostaglandins Leukot Essent Fatty Acids. 2009 Nov-Dec; 81(5-6):417-23.PL
Ultrasound may reduce lipid extraction times and increase analysis throughput of food materials. Ground flaxseed (25mg aliquots) were extracted in quadruplicate in 2:1 (v:v) chloroform:methanol, 3:2 hexane:isopropanol, 1:1 diethyl:petroleum ether or hexane with exposure to sonication at low frequencies of 20kHz with a 600W ultrasonic processor. Power was automatically varied to maintain constant amplitudes of 20%, 60% and 100% of 240microm for sonication exposures for 5, 10 and 20min, respectively. Total lipid dry weights and quantitative and qualitative fatty acids were determined. Results were compared to a standard 24-h, Folch-based, 2:1 chloroform:methanol extraction. Longer time exposures and higher sonication amplitudes were associated with increases in lipid recoveries. In particular, ultrasound-assisted extraction in 3:2 hexane:isopropanol for only 10min resulted in lipid and fatty acid recoveries similar to the 24-h standard method. Comprehensive testing on a variety of sample matrices and food products is required, but lipid extraction by ultrasound has potential to reduce sample processing time.