Entrapment of Flaxseed Oil Within Gelatin-Gum Arabic Capsules

The aim of this study was to optimize the encapsulation of flaxseed oil within a gelatin-gum Arabic (GA) matrix via complex coacervation. The effect of homogenization rates (3,000-15,000 rpm) and total biopolymer concentrations (1-2% w/v) on emulsion efficiency was studied in order to optimize the wall matrix. The physicochemical properties of the dried powder, and the capsule's ability to inhibit oxidation during storage were assessed. As homogenization rates increased from 3,000 to 9,000 rpm, the structure of the capsule transitioned from a spherical mononuclear-type to irregular-shaped multinuclear capsules. The size of the capsules and amount of non-encapsulated oil was found to increase as the total biopolymer concentration was raised from 1 to 2% (w/v). Subsequently, gelatin-GA capsules were produced with a 1:1 core-to-wall ratio at a total biopolymer concentration of 2% (w/v) and at a homogenization rate of 9,000 rpm. Formed capsules had an encapsulation efficiency of 84% and showed a protective effect against the production of primary and secondary oxidative products versus non-encapsulated oil during 25 days of room temperature storage.