M.A. Buchal, C.J. Langdon-1998
Aquaculture Nutrition, 4: 263-274
Abstract :
We describe the development and evaluation of a new microparticle for delivering low-molecular weight, water-soluble materials to suspension feeders. Spray beads successfully incorporated materials dissolved in an aqueous phase or as dry particulate, within a triacylglyceride bead composed of tripalmitin, 600 mg per g tripalmitin/400 mg per g triolein, or 600 mg per g tripalmitin/400 mg per g fish oil.
Riboflavin was successfully incorporated (up to 44 mg/g lipid) and retained (up to 98% over 24 h in seawater) as dry particles in all three mixtures of lipid. Aqueous oxytetracycline hydrochloride or polymeric dye were incorporated (45.6 mg/g lipid and 18.1 mg/g lipid, respectively) and retained best (99% and 94%, respectively) in spray beads composed of tripalmitin. The addition of triolein or fish oil to the lipid bead reduced incorporation and retention efficiencies for aqueous core materials by up to 75%.
Manila clam seed readily ingested and digested lipid microparticles, spray beads and lipid-walled microcapsules. Microparticles composed of tripalmitin were excreted with their payloads intact. Intact microparticles composed of 600 mg per g tripalmitin/400 mg per g fish oil were largely absent in faecal strands suggesting successful release and delivery of microparticle contents to clams.
Spray beads composed of tripalmitin softened with 400 mg per g fish oil represent an effective microparticle type for delivering low-molecular weight, water-soluble materials to aquatic suspension feeders.
(Oregon State University/Coastal Oregon Marine Experiment Station, Newport, OR, USA, E-mail: mbuchal@ultraconnect.com)