A phase inversion based nanoemulsion fabrication process to encapsulate vitamin D3 for food applications

Abstract

A phase inversion based nanoemulsion fabrication process was developed to encapsulate vitamin D₃ by blending caprylic-/capric triglyceride (CCTG), Leciva S70, Kolliphor® HS 15, vitamin D₃ and aqueous phase (sodium chloride solution). In order to find out nanoparticle formation zone (NFZ), a ternary diagram was plotted with 41 possible combinations of three components CCTG, Kolliphor® HS 15 and aqueous phase. Out of forty one, only twelve combinations resulted in formation of stable nanoemulsion where the composition varied between 10%-40% (v/v), 10%-25% (v/v) and 35%-80% (v/v) for Kolliphor, CCTG and water respectively. Further, these 12 nanoemulsions were investigated for their particle size, zeta potential, emulsion stability, encapsulation efficiency and release kinetics (simulated digestion) of vitamin D. The nanoemulsion (NE-20) fabricated with 30% (v/v) Kolliphor, 20% (v/v) CCTG and 50% (v/v) aqueous phase was found to be the most suitable with respected to zeta potential, emulsion stability and encapsulation efficiency and also demonstrated high bioavailability of vitamin D as compared to other combinations and hence was selected for further physiochemical studies. The selected nanoemulsion was also investigated for particle size and zeta potential and stability of vitamin D₃ retention under different environmental stress conditions (i) temperature and humidity: (a) accelerated condition: 45 ± 2 °C and RH 75 ± 5%, (b) ambient condition: 25 ± 3 °C and RH 65 ± 5% and (c) refrigerated condition: 6 ± 2 °C and RH 55 ± 5% (ii) pH (3-7) under refrigerated condition and (iii) ionic strength: NaCl concentration (0 mM, 250 mM, 500 mM and 750 mM) under crefrigerated condition. Fourier transform infrared spectroscopy and High Perfomance Liquid Chromatograpy technique were used to study physico-chemical stability of encapsulated vitamin D₃ in the developed nanoemulsion. The sensory evaluation also indicated the acceptability of the selected nanoemulsion the purpose of fortification for beverages.

Keywords: Nanoemulsion; Particle size; Phase inversion method; Release; Vitamin D(3); Zeta potential.