Free amino acid leaching
from a protein-walled microencapsulated diet for fish larvae
M. Yúfera, S. Kolkovski, C. Fernández-Díaz, K.
Dabrowski-2002
Aquaculture,
214(1-4) : 273-287
Abstract:
The leaching loss of free amino acids (FAA) from an
experimental protein-walled microencapsulated diet (MC) for larval fish
after immersion in water was measured and compared with leaching loss from a
gelatin microbound diet (MB) containing the same dietary ingredients. The
loss of FAA (as a percentage of total dietary FAA) was significantly higher
in the MB diet compared to the MC diet. After 5 min of re-hydration, 22% of
FAA were leached from the MB diet compared with 8% from the MC diet. After
60 min, 85% of FAA from the MB diet were leached into the water compared to
17% from the MC diet. The addition of free lysine to protein-walled
microcapsules (MC-L) was also investigated to determine the suitability of
MC for delivering specific FAA. Lysine was incorporated into the particles
with an efficiency of 7.5% and accounted for approximately 60% of the total
FAA in the diet. The loss of this amino acid from MC-L after 60 min of
immersion was 1.4%. The loss of specific FAA from MB and MC diets was found
to be negatively and positively correlated to the hydrophobic character
(hydropathy index) of each FAA, respectively. These results support the use
of protein-walled microcapsules as a vector for specific dietary amino acids
using a macronutrient-balanced diet.
(Instituto de Ciencias Marinas de Andalucía (CSIC),
Apartado Oficial 11510, Puerto Real, Cádiz, Spain, e-mail: manuel.yufera@icman.csic.es)