Abstract
The work aimed to encapsulate oils recovered from brewer’s spent grain by particles from gas saturated solutions technique using supercritical carbon dioxide as solvent and polyethylene glycol as wall material. The process conditions (pressure and temperature) and the wall material content were tested to produce an ingredient with enhanced physical properties and oxidative stability. Among the applied pressures (10, 20, 30, and 35 MPa), temperatures (45 and 55 °C) and oil to polyethylene glycol mixing ratios (1:5; 1:3, 1:2.5 and 1:2), the highest encapsulation efficiency was obtained at 20 MPa, 55 °C with an oil to polyethylene glycol mixing ratio equal to 1:3. With such conditions, the particles reported 73.5 ± 1.5% of encapsulated oil, with 58.1 ± 2.8% of the powder showing a mean diameter equal to 375 μm. The bulk and tapped densities were equal to 0.35 ± 0.01 and 0.38 ± 0.01 g · cm−3, while the wettability resulted of 3.2 ± 0.01 min. Furthermore, the encapsulated oil was oxidative stable up to 130 ± 3.2 h at 40 °C, as measured by isothermal calorimetry and peroxide value. The findings showed the potentials of particles from gas saturated solutions technique for the production of an ingredient for food, cosmetic and pharmaceutical applications.