Particle formation of an edible fat (rapeseed 70) using the supercritical melt micronization (ScMM) process

The supercritical melt micronization (ScMM) process, also known as particles from gas saturated solutions (PGSS) was applied, in a continuous operated pilot plant, for the particle formation of the edible fat, rapeseed 70 (RP70). The effect of variables like the CO2 concentration, the melt temperature and the atomization pressure were studied in order to investigate particle morphology, density and the particle size distribution. The experiments were performed at CO2 concentrations between 0 and 50 wt%, atomization pressure between 70 and 180 bar and melt temperature between 60 and 100 °C. Particles obtained as a function of the CO2 concentration, showed completely solid, spherical–hollow and aggregated particles with a decrease in particle mean size as the concentration of CO2 was increased. The results obtained as a function of atomization pressure showed no significant influence on particle morphology and size distribution. Experiments carried out as a function of the melt temperature showed distorted, spherical–hollow and aggregated particles. Furthermore, a theory was developed to explain the mechanism for particle formation as a function of the CO2 concentration and the melt temperature. The crystallinity of the final product of RP70, showed an alpha polymorph with a crystallinity of 84%.