Etude comparative des voies de valorisation des sous-produits de poulpe (0ctopus cyanea) en alimentation piscicole : autolysat et farine »

Abstract

Biotechnology is a tool to develop a new way of improving the values of byproduct
from octopus transformation chain. The research conducted at VALOREMAR aims at digging
the properties and efficiency of flour and autolysate on fish rearing. The yield and the protein
rate of the flour were studied by using two differents drying temperatures of the pressed cake.
Furthermore, the by-products conservation (fresh or frozen) and the influence of the
hydrolysis conditions (temperature 40 ° C and pH 2) and (50° C and pH 3) was studied on the
yield, the degree of hydrolysis and the protein rate of the autolysat. An improvement of the
status of these two parameters were noticed when heat is brought at 65°c (15,03 ± 0,54 % et
57,70 ± 0,14 %) compared to a drying at 100°c (12,21 ± 0,78 % et 57,17 ± 0,05 %). In fact,
the high level of hydrolysis (15,48 ± 0,41 %) with a mean yield of 9,38 ± 0,69 % and a total
protein rate of 61,75 ± 0,12 % were registered with the autolyze driven at pH 2 under 40°C.
The feeding efficiency test conducted at PRADRA laboratory on tilapia Oreochromis
niloticus fries were evaluated on mean weight gain, final biomass and conversion ratio. After
7 weeks of rearing, high zootechnic performances were obtain with H50 and H25 with which
the final mean biomass and the conversion ratio were respectively 74,45 ± 3,46g/2,93 and
70,35 ± 0,07g/3,68 against 54,79 ± 3,66g/4,09 for the witness food. Furthermore, the
statistical analysis confirm the significant difference (p<0,05) between the fry batches (F50 et
F50), (F25 et witness), (H25 et witness) et (H50 et witness).