Designing of ω-3 PUFA enriched biocompatible nanoemulsion with sesame protein isolate as a natural surfactant: Focus on enhanced shelf-life stability and biocompatibility

Natural polymeric proteins, isolated from sesame meal, had already shown promise as potent nutraceutical. This polymeric protein was employed as a natural alternative surfactant for designing a nanoemulsion based delivery system for omega-3 PUFA rich fish oil (FO) in the present study. The process parameters of the high pressure nanoemulsification were optimized with the CCD guided RSM analysis. Results with highest desirability [cumulative droplet size 125.87 +/- 2.54 nm, PdI 0.199 +/- 0.01 and D90 Particle size 268.98 +/- 13.89 nm] was obtained with 40 Kpsi homogenization pressure and 10 homogenization cycles and upto 1.5% (w/v) FO. The nanoemulsion formulation with SPI at 0.5% (w/v) concentration in combination with Tween 20 and Span 80 (1:1) had minimized the hydrodynamic droplet size to 89.68 +/- 2.375 nm and also enhanced the shelf-life stability of the nanoformulations substantially, along an 8 week long storage period. Inclusion of SPI as surfactant also contributed to >= 90% of fatty acid release from the fish oil rich nanoemulsion droplets, at a steady gradient during 120 min of simulated two-step in vitro digestion. The MTT assay had confirmed the formulation to be non-toxic towards rat PBMCs. The informations obtained in this study will facilitate the application of SPI to formulate nutraceuticals-loaded nanoemulsion delivery system with better functional benefits.