A comparative study of the efficiency and quality of six surfaces in drying Haplochromis SPP. (Nkejje) at Rubare Fish Landing Site in Lake Mburo protected area

Abstract

The study compared the efficiency and quality of the currently used traditional fish drying surface ‘Bare ground’ to five newly modified and improved surfaces in drying Haplochromis spp. (nkeje). The study was done at Rubare fish landing site in Lake Mburo protected area. Altogether, 240 racks with Haplochromines were used in the completely randomized experimental design. Five surfaces namely; Plastic palette fabric, burnt clay brick, Popcorn concrete, refined stone bed and Mass concrete were constructed within a period of seven days. Their efficiency in drying the fish was compared to the traditional ‘bare ground’ drying surface based on the following parameters; rate of moisture loss, microbial content, dried fish body shape (curvature) and community response towards the newly constructed surfaces. All the six drying surfaces were found to be equally efficient in regards to the rate of moisture loss as there was no significant difference (p>0.05) in performance amongst the surfaces. On day three, the mean percentage moisture loss was highest on Popcorn concrete (41.35±4.90), followed by Refined stone bed (39.73±4.90), Burnt clay brick (37.85±4.43), Mass concrete (37.55±4.65), Bare ground (34.54±4.43), and lastly Plastic palette fabric (26.50±4.43). Comparison of the drying surfaces based on microbial counts revealed considerable reduction in Total Plate Counts of, Escherichia coli, and Staphylococcus aureus. Staphylococcus aureus and Escherichia coli were eliminated after drying on all surfaces whereas no Salmonella organisms were detected in all the samples. The TPC (cfu/ml) of microbes reduced most on Plastic palette fabric from 2.3x108 before drying to 6.0x107 after drying, followed by Mass concrete from 1.5x108 to 6.0x107 and Popcorn concrete from 1.0x108 to 2.0x107. The TPC however increased significantly on ‘Bare ground’ from 1.8x108 to 4.0x108. Bare ground emerged as the best drying surface producing the least curved/bent number of fish. Although all the drying surfaces were equally efficient in drying the Haplochromis spp., bare ground had a worrying increase in TPC and S. aureus. This implies that one of the improved drying surfaces especially the Plastic palette fabric and the Mass concrete could substitute bare ground in daily use so as to produce more quality fish.