In the present study, the potential of low-melting point lipids, namely methyl
palmitate (MP) and menhaden stearine (MS), were studied for delivery of water-soluble
materials to fish larvae.
Addition of the solid emulsifier, sorbitan monopalmitate (SMP) resulted in higher
RE compared to the liquid emulsifier sorbitan sesquioleate (SSO). Additions of SMP
were found to have a positive effect on the stability of lipid spray beads (LSB) at
concentrations >10% (w/w) of lipid. LSB were shown to retain riboflavin with the
highest RE when the lipid matrix was composed of a mixture of MP+10% SMP+1O%
ethyl cellulose (w/w). Use of MP facilitated digestive breakdown of LSB by larvae of
zebrafish, Brachydanio rerio, and glowlight tetra, Hemigrammus erythrozonus, as
indicated by release of riboflavin from ingested LSB.
LSB composed of MS performed better than LSB composed of MP when
particulate glycine was incorporated within LSB. Highest retention efficiencies (RE) and
delivery efficiencies (DE) were achieved by LSB composed of 100% MS. RE and DE of
LSB were further improved when glycine was encapsulated as aqueous droplets rather
than in a particulate form. The overall performance of LSB containing tyrosine showed
that nutrients with similar water-solubilities to tyrosine can be very effectively delivered
to early fish larvae. Visual observation indicated that LSB composed of 100% MS were
broken down by larvae of clownfish, Amphiprion percula.
Zein-bound particles (ZBP) were not efficient in delivering riboflavin to fish
larvae due to high leaching rates. In an attempt to improve ZBP, we developed complex
particles (CP) containing LSB incorporated in a dietary mixture bound by zein, to obtain
a single particle type. The potential of LSB for delivery of free amino acids (FAA) was
evaluated when LSB were incorporated within CP. RE and DE for tyrosine were
significantly greater than those for alanine, glycine and serine. There was a significant
inverse correlation between RE for FAA and their solubilities where FAA with low
solubilites resulted in higher RE. Development of CP with high RE and DE for amino
acids is an important step towards formulating a diet to allow early weaning of fish larvae
onto artificial diets. / Graduation date: 2003
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/30807 |
| Date | 26 November 2002 |
| Creators | Onal, Umur |
| Contributors | Langdon, Chris J. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
Page generated in 0.0021 seconds