Abstract:
Proximate analysis for moisture, crude protein, crude fat and total ash was carried out
on dagaa (Rastrineobola argentea), a small pelagic fish specie found in Lake
Victoria. The first phase of the study involved sampling of fresh, sundried (for 1 day,
2 days, 3 days, 4 days) and retail market dagaa. The second phase of the study
involved pre-washing of fresh dagaa with selected solutions namely, salted solution
(3% NaCl), chlorinated solution (100 ppm) or potable tap water (control) and
thereafter oven-drying the respective pre-washed samples at 30
C
(23hrs) or 50
o
o
C (31hrs), 40
o
C (15hrs). Results showed that the crude protein composition of fresh
dagaa (74.4% dry weight basis, dwb) was significantly higher (p<0.05) than values
in market samples (62.5% dwb). After oven-drying at 30
C, the salted-wash
treatments resulted to significantly lower (p<0.05) crude protein content of 60.4%
(dwb) when compared with the chlorinated (64.6% dwb) and control-wash treatments
(64.1% dwb).The crude fat content in fresh dagaa (14.8% dwb) was significantly
o
higher (p<0.05) than levels in market samples (13.9% dwb).The salted-wash
treatments showed significantly lower (p<0.05) crude fat content (15.9% dwb) than
the chlorinated (17.0% dwb) and control (16.9% dwb) wash treatments after ovendrying
at 30
o
C.The total ash content in fresh dagaa (10.3% dwb) was significantly
lower (p<0.05) than levels in market samples (13.5% dwb).The salted and
chlorinated-wash treatments exhibited significantly higher (p<0.05) total ash content
(19.9%, 16.7% dwb, respectively) than the control-wash treatment (15.9% dwb) after
drying at 40
o
C after washing with
chlorinated (100ppm) solution was suggested with regard to the optimal retention of
the crude protein and fat levels of the dried dagaa.These conditions are achievable at
the local community level through use of solar driers whereas sodium hypochlorite
products are accessible to most of the households involved in dried fish processing.
C. In this study, oven-drying of dagaa at 40
o
