Extraction of camelina mucilage with ultrasound and high flow rate fluid circulation

Abstract

As the outermost layer of many oleaginous seeds, mucilage can be extracted by different shear forces. At lab scale, ultrasound is an effective extraction method and is associated here with hydrodynamic forces on a higher scale. In the example of camelina mucilage, an ultrasonic tubular reactor and a recirculating pump are used separately and combined with a response surface methodology. With a seed concentration of 10 % in water, mucilage extraction yields of 6.9 ± 1.5 % and 6.6 ± 0.3 % are obtained after 55’ of pulsed ultrasonic treatment with a 3 L ultrasonic tubular reactor and a lab scale (100 mL) ultrasonic probe, respectively. High flow rate recirculation (100 L/min) used alone allows yields of more than 10 %. Extraction efficiency then depends directly on the rheological behavior of the medium and allows a high seed concentration (up to 15 %). The combination of ultrasounds and high flow rate circulation reveals a high importance of ultrasound on protein composition and rheological behavior of mucilage while extraction yield, protein and ash content are mainly controlled by circulation time.