Characterisation and emulsifying properties of microwave pretreated camelina seed mucilage

Abstract

In this study, microwave (MW)-assisted extraction was used to obtain mucilage from Camelina sativa seeds. MW pretreatment was applied for 0, 2.5, 5 and 7.5 min and then conventional heating was conducted (55 °C for 2 h). The extracted mucilage was spray dried. The MW-assisted extraction method (2.02%–2.50%) had higher extraction yield for camelina seed mucilage than the conventional heating method (1.91%) (P < 0.05). The emulsifying properties of the mucilages were compared with those of gum Arabic and all emulsions displayed shear thinning behaviour (pseudoplastic, n < 1). The apparent viscosity of the conventional, 2.5, 5 and 7.5 min MW mucilage emulsions were 15.83, 14.48, 7.91 and 7.56 cP, respectively, at 10 s−1. MW pretreatment improved physical stability and resulted in a reduction in the droplet size of mucilage-stabilised emulsions with increasing process time. The highest droplet size belonged to the conventional mucilage emulsion (d32, 4.43 μm), while the lowest belonged to the 7.5 min MW mucilage emulsion (d32, 2.08 μm) (P < 0.05). The results highlight the advantages of using MW pretreatment for mucilage extraction and the potential of using camelina seed mucilage as a natural emulsifier.