Nano-encapsulation of fish oil and garlic essential oil by a novel composition of wall material: Persian gum-chitosan

This study investigated nano-encapsulation of fish oil (FO) and garlic (Allium sativum L.) essential oil (GEO) using Persian gum (PG) and chitosan (Chi) as wall materials (at the ratio of 2:1, 1:1 and 1:2 (w/w) and core/wall ratio of 10:2 (w/w)), applying the electrostatic layer-by-layer deposition method. Our findings revealed that PG:Chi 2:1 ratio was the best combination of wall material, giving good zeta potential (33.4 ± 1.6 mV), maximum emulsion stability, surface tension (56 ± 0.3 mN m−1) and viscosity (1.09 ± 0.04 Pa s) while maintaining minimum droplet size (23.19 nm) and PDI (0.120 ± 0.002). Consistent with the emulsion studies, the PG:Chi 2:1 ratio gave nano-capsules with the best reconstituted emulsion properties. This includes zeta potential of 34±1 mV, droplet size in nano range (mean size, 65 nm) with good stability and low dispersibility (PDI, 0.385 ± 0.004). From scanning electron microscopy (SEM), the FO-GEO nano-capsules show agglomerated morphology with spherical particles. The success of FO-GEO encapsulation was confirmed by the results obtained from differential scanning calorimetry (DSC), X-Ray Diffraction (XRD) and Fourier-Transform Infrared Spectroscopy (FTIR) analyses. The physicochemical characteristics and thermal stability indicated that such nano-capsules have promising use in pharmaceutical and food industries for delivery of FO-GEO.