EFFECTS OF SURFACE-ACTIVE AGENT ON THE SIZE, SHAPE AND HARDNESS OF MICROCRYSTALLINE CELLULOSE MAIZE STARCH PELLETS PREPARED BY AN EXTRUSION-SPHERONIZATION TECHNIQUE/

The effects of non-ionic surface-active agent on the size, shape and h ardness of microcrystalline cellulose/maize starch pellets prepared by an extrusion-spheronization technique were studied. Purified water co ntaining 0 to 3% (w/w) polysorbate 80 was used as a granulation liquid . All pellet formulations obtained were well-flowing and mechanically very strong. The addition of a non-ionic surface-active agent decrease d the amount of fines but increased the over-sized pellets. The inclus ion of surface-active agent also improved the shape and the surface ch aracteristics of the pellets. The pellets became rounder, but it was o bvious that there was only slight improvement after adding more than 1 % surface-active agent in the granulation liquid. The roughness of the pellet surfaces decreased in relation to the concentration of the sur face-active agent. The results suggest that the addition of non-ionic surface-active agent improves the wetting and thereby the rounding of pellets containing microcrystalline cellulose and native maize starch as a co-filler, but the effect is not sufficient to produce fully roun d pellets.