Nano-encapsulation of coenzyme Q10 using octenyl succinic anhydride modified starch

•Freeze drying enhanced nanoemulsion stability by 150%.•Emulsion was stable through testing at 90°C for 3.5h.•Emulsion stability in a 0.1M phosphate–citrate buffer peaked at 8days.•Encapsulation efficiency >98% was verified by a hexane rinse and a CO2 SFX.•Particle size stability is also an important factor in emulsion stability. Octenyl succinic anhydride modified starch (OSA-ST) was used to encapsulate coenzyme Q10 (CoQ10). CoQ10 was dissolved in rice bran oil and incorporated into an aqueous OSA-ST solution. High pressure homogenisation of the mixture was conducted at 170MPa for 56 cycles. The resulting emulsion had a particle size range of 200–300nm and the absolute zeta potential varied between 8.4 and 10.6mV. CoQ10 retention of the emulsion and freeze dried products, determined by a hexane rinse, was 98.2%. Reconstitution of the freeze dried product in Mcllvaine citrate–phosphate buffers with pH values of 3–5 and temperatures at 4 and 25°C had very little effect on the range and distribution of the nanoparticles’ size. The inflection point of the zeta potential and pH plot occurred at the first pKa of succinic acid (pH 4.2), indicating succinate as the main influence over zeta potential.