The effect of brine solution on the proximate composition and microbial load of Clarias gariepinus

Abstract

The use of brine solution on the proximate composition analysis and microbial load of fish was studied. There were four treatments which were replicated thrice. The treatment varied with time the test fish were immersed in salt solution. Treatment 1 was smoked directly without immersing in salt solution and served as the control; treatment 2 was soaked for 1 hour in salt solution before smoking, treatment 3 for 2 hours, while treatment 4 was for 3 hours before smoking. Smoking was done using a drum kiln. The fish samples (Clarias gariepinus) which were 147 in number weighing 1kg each were decapitated and washed with clean water before being subjected to the various treatments. The fish so preserved was stored for 21 days. An initial Proximate composition and microbial test of the raw fish sample (control) was done and a final Proximate composition analysis was also done on the treated fish samples at the end of the experimental period. Microbial analysis was done weekly for the entire storage period. Results showed that there were significant differences (p<0.05) in moisture content between the initial and the final moisture content, except for treatment 2. There were no significant differences (p>0.05) amongst the treatments in both the total microbial load and fungi load, but however, there exist a significant difference (p<0.05) across the week in the bacterial load. The number of occurrence in the fungi increases with storage time. Treatment 4 gave a better result in microbial load and fungi growth, as well as the proximate composition analysis. It is recommended therefore that fish should be immersed in brine solution for upwards of 3 hours before smoking.

Keywords: nutritive value, shelf life, spoilage, smoking