factors influencing formation and properties of nanoemulsion stabilized by sodium caseinate and tween 80

in this study formation and properties of o/w emulsion stabilized by a mixture of sodium caseinate (2, 5 and 10 wt %) and non-ionic emulsifier tween 80, sorbitan mono-9-octadecenoate, (0, 0.5, 1 and 1.5 wt %) were investigated at various ph values(3, 5 and 7) and calcium ion concentrations (0, 0.2, 0.4 and 0.6 wt%). emulsion samples were prepared by using a sonicator with a nominal power output of 750 w and an operating frequency of 20 khz. sonication of samples was carried out in a temperature-controlled chamber at a constant temperature of 20 ºc and the highest acoustic power available for 3 minutes. the results showed that increasing the concentration of sodium caseinate and tween 80 generally reduced the size of droplets, although it was observed that tween80 adversely affected the size of droplets at higher concentration under acidic conditions. moreover, ph and calcium ion significantly affected the diameter and specific surface area of droplets (p<0.05). the smallest droplets formed in the absence of calcium ion, and at ph = 7, 10% sodium caseinate and 1% tween 80. it was found that the size of droplets grew in the presence of calcium ion. however, at very low concentration of calcium ion the increase in the size of droplets was insignificant (p<0.001).