2.2. Emulsion preparation
Water-in-oil emulsions were produced by homogenising
10 wt.% aqueous phase (with 0–10 wt.% CaCl2 and 0–80 wt.% glycerol)
with 90 wt.% sunflower oil (with 0.1–9 wt.% PGPR). The low
weight per cent of water was selected to minimise affects of droplet
collision and for the majority of experiments 9 wt.% PGPR was
used to ensure that the emulsifier concentration was in excess to
minimise coalescence.
A coarse emulsion was prepared by using a Silverson mixer at
7500 rpm for 120 s at room temperature. Nanoemulsions were
produced by passing the coarse emulsion through an air-driven
Microfluidizer fitted with a cooling tube submerged in equal
proportions of ice and water (M110S fitted with a Y-type chamber,
Microfluidics, Newton, MA, USA) or a high pressure valvehomogeniser (NS1001L PANDA, GEA Niro Soavi, Italy) for up to 5
passes from 50 to 100 MPa.