Use of Alginate for the Encapsulation of Balanced Feed for Aquaculture Applications

Abstract

This study explores the use of alginate-based polymeric microcapsules as a cost-effective and sustainable alternative for larval fish feeding. For this, a locally developed balanced feed, with protein and lipid profiles similar to Artemia, was used as the core material. Various encapsulation formulations were evaluated using food-grade sodium alginate (0.4 to 1.0 % w/v) and feed concentrations (5 to 25 % w/v). Two encapsulation methods were tested: syringe dripping and compressor-assisted spraying. The resulting microcapsules were analyzed by optical microscopy and UV-Vis spectrophotometry. Syringe encapsulation with 25 % feed and 0.6 % alginate yielded 2.5 mm spheres with an encapsulation efficiency of 80 %. Spraying, using 10 % feed and 0.6 % alginate, produced microparticles with a diameter of 0.4 mm, comparable to Artemia size. Both formulations exhibited good stability in liquid medium over 15 days at room temperature. These results highlight the potential of alginate as an encapsulating matrix for aquaculture feed, offering a viable alternative to reduce costs and decrease dependence on imported Artemia, thus supporting more resilient local aquaculture systems.