Preparation of Microcapsules Containing Artificial Diet for Tropical Fishes with Spray Gelling Method

Abstract

The microcapsules containing the artificial diet for tropical fishes were prepared with the spray gelling method in order to prevent water environmental pollution. The carboxymethyl cellulose sodium aqueous solution, in which α-tocopherol droplets containing the powdery artificial diet were dispersed, was dropped or sprayed into the chitosan aqueous solution. Microcapsules were prepared by forming polyionic complex shell made from chitosan and carboxymethyl cellulose sodium. In the experiment, the concentration of carboxymethyl cellulose sodium (CMCNa) was mainly changed to investigate the effect on the diameters of microcapsules, the content and the microencapsulation efficiency. The microcapsules couldn’t be prepared with the concentration of carboxymethyl cellulose sodium less than 3.0 wt%. The microcapsules were the core-shell type. The diameters of microcapsules were increased with the concentration of CMCNa and the microencapsulation efficiency of ca. 100% could be obtained by the preparation method presented in this study. The microcapsules were found to be eaten well by tropical fishes and to prevent water environmental pollution.