Echium oil with oxidative stability increased by emulsion preparation in the presence of the phenolic compound sinapic acid followed by dehydration by spray and freeze drying processes

Echium oil is rich in omega-3, however, is unstable. The objective of this work was the co-encapsulation of echium oil and sinapic acid (SA) by emulsification using Arabic gum as emulsifier/carrier, followed by spray or freeze-drying. Eight treatments (S0, S200, S600 and S1000: particles spray dried with different concentrations of SA; L0, L200, L600 and L1000: particles freeze dried with different concentrations of SA) were analyzed in relation to microscopy, water activity (Aw), hygroscopicity, moisture, solubility, particle size, X-ray diffraction, thermogravimetry and accelerated oxidation. Particles of rounded shape and undefined form were obtained by spray and freeze-drying, besides ideal physicochemical properties for application (values from 0.091 to 0.365, 3.22 to 4.89%, 57 to 68% and 2.32 to 12.42 mu m for Aw, moisture, solubility and particle size, respectively). All treatments protected the oil against oxidation, obtaining induction time of 5.31 h for oil and from 7.88 to 12.94 h for treatments. The better protection to oil was obtained with it emulsified and freeze-dried (L600); the encapsulation increased oxidative stability of the oil, besides facilitating its application over the fact the material is in powder form.