Ultrasonication as a highly efficient method of flaxseed mucilage extraction

Abstract

Three methods of aqueous extraction of flaxseed mucilage (magnetic stirring, microwaves and ultrasounds) were compared and tested, from whole flaxseeds at a concentration of 5% (w/v) and a temperature of 50°C. While microwaves are less efficient than a magnetic stirring, ultrasound-assisted extraction showed the highest mass transfer coefficient and a higher order kinetic. 7% of the seed mass were extracted after only 30min of treatment.Ultrasound assisted extraction decreases the intrinsic viscosity of the mucilage from 12.5dL/g (for magnetic stirring) to 6.2dL/g, and the weight-average molecular weight of the largest polysaccharides from 1.5×106Da to 0.5×106Da, whilst having a limited impact on protein content and monosaccharide composition.