Microencapsulation of pomegranate (Punica granatum L.) seed oil by complex coacervation: Development of a potential functional ingredient for food application

The objective of this study was to develop a functional ingredient containing punicic acid, a bioactive conjugated linolenic acid isomer, via microencapsulation of pomegranate seed oil (PSO) by complex coacervation. Whey protein and gum Arabic were used as encapsulating agents and spray drying was applied as a hardening step. The effects of total polymer concentration (Cp) (2.2–7.8 g/100 mL) and wall material:oil ratio (WM:Oil) (0.5–5.0) on microparticles physical-chemical characteristics (oil retention, microencapsulation efficiency (ME), punicic acid content and particle size) were evaluated, according to a 22 rotatable central composite design. Microparticles' morphology and surface composition were also assessed. Both Cp and WM:Oil ratio affected oil retention, ME, punicic acid content and particle size. Intermediate values of Cp and WM:Oil ratio were considered the best conditions for PSO encapsulation, resulting in the highest oil retention (near 100 g/100 g; and punicic acid content, near 64 g/100 g fatty acid). High Cp and low WM:Oil ratios promoted microparticles’ agglomeration. PSO microparticles rich in punicic acid were successfully produced by complex coacervation, enabling future use of PSO as a functional ingredient in food products. •Pomegranate seed oil was microencapsulated by complex coacervation.•Cp and WM:Oil ratio affected microparticles' physical-chemical properties.•Pomegranate seed oil microparticles showed a high retention of punicic acid.•Cp and WM:Oil ratio influenced microparticles' morphology and surface composition.•A potential functional ingredient for food applications was successfully obtained.