Scale-down emulsion homogenization: Conditions to mimic pilot homogenizer depending on the emulsifier

Abstract

The standard tool for emulsification during formulation trials is a homogenizer, which unfortunately requires too much raw material and is time consuming. A lab-scale process using a rotor-stator shearing step followed by ultrasound treatment was designed, both with lecithin and whey protein, for emulsification as efficient as in pilot-plant trials. Ranges for the lab-scale process were defined (rotor-stator: 5 min, 5000–10000 rpm; sonication time: 2–10 min). Process conditions were identified to obtain both emulsions with the same structure at lab and pilot scales: for lecithin, respectively shearing at 10000 rpm/10 min sonication and high pressure for both pilot stages. However, due to protein denaturation, some conditions differed for whey proteins: shearing at 5000 rpm instead of 10000 rpm (all the other parameters being unchanged). Finally, recommendations concerning the position of the ultrasound probe and temperature control are provided to insure good reproducibility.