The present study is motivated by the development of solid lipid nanoparticles (SLNs) for food applications. A focus of the study is the use of a factorial design to optimize the preparation variables. SLNs were prepared by hot homogenization at 60 degrees C. Cocoa butter was used to form the lipid core and the surfactant blend used to emulsify and stabilize the system was a mixture of sodium stearoyl-2-lactylate (SSL) and mono- and diglycerides of fatty acids (MDG). The particle characteristics and stability of obtained SLN-suspensions were investigated. Moreover, the effect of various cooling conditions on the properties of SLNs and the storage stability during a period of three months were examined. Results proved that cocoa butter is suitable to prepare SLNs with a food-grade quality where the optimized preparation variables resulted in a particle size of 112.7 nm. (C) 2018 Published by Elsevier Ltd.