Commercially available sunflower meal (SFM) was subjected to extrusion
processing and then tail-end dehulling (using multiple vibrating screens) to nutritionally upgrade the
protein content to 40.9% on a dry weight basis (db) and improve its digestible energy content. A
basal and four test diets were formulated by replacing fishmeal protein in the dietary mix with
increasing equal increments of nutritionally upgraded SFM (maximum dietary concentration 27%;
db). The resulting five diets (-49% protein and -18.5% lipid; db) were fed to fifteen groups of post-juvenile
Atlantic salmon (n=50/group; 3 groups/diet) over an 84-day period. The performance of
Atlantic salmon (initial mean weight - 116 g) was judged by the following parameters: weight gain,
specific growth rate, feed intake, feed efficiency, protein efficiency ratio, percent protein deposited,
gross energy utilization, and percent survival. Also, proximate analyses of both whole bodies and
muscle samples (fillets) were undertaken on salmon from day 0 and 84. Atlantic salmon fed the basal
diet (0% SFM) and the four test diets (contained SFM) did not differ significantly (p > 0.05) with
respect to any of the preceding performance parameters.
To determine the effect of using SFM in the diet on the flesh quality attributes of
Atlantic salmon, sensory evaluation (14 panelists) was conducted over 9 sessions (after 4 one-hour
training sessions) to test salmon quality attributes of aroma, flavor, foreign flavor and texture, using
a descriptive sensory ballot. Sensory panel results indicated that salmon - aroma, flavor and texture
were similar (p > 0.05) across the five diets. However, fillets from salmon fed diets A (0% SFM) and
E (27.1% SFM) and diets B (6.8% SFM) and E were significantly (p < 0.05) different, in perceptible
foreign flavors, respectively. Salmon fillet color, quantified using Salmofan™ and Hunter Lab L, a
and b scores, did not differ (p > 0.05) across the diets. In addition, Salmofan™ scores were positively
correlated (r = 0.86) with Hunter (a) scores. Headspace gas chromatography (GC) of volatile
compounds collected with solid phase micro-extraction fibers (SPME) was conducted using cooked
salmon fillets. Results from GC were analyzed by the principal component similarity (PCS)
technique and they further corroborated those obtained from foreign flavor analysis by a sensory
panel.
In conclusion, the incorporation of ≤ 27.1% of SFM in the basal diet by partial
replacement of premium quality fishmeal resulted in no adverse effects on growth of Atlantic salmon
reared in seawater. But foreign flavors perceived by panelists were significant (p < 0.05) in the fillets
from salmon fed diet E (27.1% SFM). Hence, the highest dietary SFM concentration used in the
present study appeared to contribute towards some foreign flavors in the flesh, but further research is
needed to confirm and possibly extend this finding if higher dietary concentrations of SFM are
employed.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:BVAU.2429/12045 |
| Date | 05 1900 |
| Creators | Gill, Navneet |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Relation | UBC Retrospective Theses Digitization Project [http://www.library.ubc.ca/archives/retro_theses/] |
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