Abstract
Sub-micron sized particles have attracted much interest in recent years because of their unique properties in physics and chemistry as well as their potential application in industry. In this paper we evaluated two different processing techniques on the preparation of β-carotene dispersions and their influence on the particle size distribution. The present work also studies the influence of various experimental parameters on the size distributions obtained. β-carotene dispersions were prepared from coarse β-carotene crystalline (with or without addition of triolein) as dispersed phase and water containing emulsifier as continuous phase. These two phases were premixed and subjected to treatments using a high-speed bead mill, and a high-pressure homogenizer. The β-carotene dispersions were characterized by low-angle laser light scattering and scanning electron microscopy. The results showed that the dispersions in size, size distribution and shape were strongly affected by the two processing techniques and various experimental parameters. The drastic size reduction of β-carotene dispersions was observed after first 15 min of bead milling (at rotation speed of 2000-4000 rpm) and after one passage through the high-pressure homogenizer at 10-140 MPa. Both high-pressure homogenization and bead milling appear to be suitable for the preparation of β-carotene dispersions. In general, the mean diameter of β-carotene dispersions ranging from 80-1000 nm was observed in this study.
