The effects of rheological properties of wall materials on morphology and particle size distribution of microcapsule
Y. Xie, A. Wang, Q. Lu, M. Huihttps://doi.org/10.17221/49/2009-CJFSCitation:Xie Y., Wang A., Lu Q., Hui M. (2010): The effects of rheological properties of wall materials on morphology and particle size distribution of microcapsule. Czech J. Food Sci., 28: 433-439.
The effects of rheological properties of the wall materials on the morphology and particle size distribution of microcapsules prepared by spray-drying were evaluated. Gelatin-sucrose (Gel-Suc), gelatin-peach-gum-sucrose (Gel-PG-Suc), and HI-CAP 100 were used as wall materials with vitamin A as a model core material. Scanning electron microscopy (SEM) showed that microcapsules produced with Gel-Suc exhibited cracks while Gel-PG-Suc produced a smooth surface with few pores, and HI-CAP100 a rounded surface containing characteristic concavities. The volume average diameter (D4,3) showed significant variations from 73.9 ± 1.02 µm and 68.7 ± 0.85 µm to 29.9 ± 0.94 µm (P < 0.05). Rheometry indicated that the wall paste viscosity was inversely proportional to the shear rate. Viscosity ranking was Gel-Suc > Gel-PG-Suc > HI-CAP 100. Gel-Suc showed the highest elastic modulus (G') and viscous modulus (G'' values), followed by Gel-PG-Suc and HI-CAP 100. Gel-Suc was associated with moderate quantities of broken microcapsules while HI-CAP 100 generated numerous microcapsules with characteristic dents generated during spray-drying.Keywords:
microcapsule; wall materials; rheological properties; morphology; particle size; spray-drying