The Shelf life of Solar Tent Dried and Open Sun Dried Diplotaxodon limnothrissa (Ndunduma)-Pisces; Cichlidae

The study evaluated changes in chemical, physical, microbial quality of solar tent dried and open sun dried Diplotaxodon limnothrissa fish species from Malembo landing site after 9 weeks of storage at ambient temperature. The shelf life of solar tent dried and open sun dried Diplotaxodon limnothrissa fish species was estimated at 7 and 3 weeks respectively. Spoilage indicators Total Volatile Basic Nitrogen (g/100mg) and pH range were 15.45-17.31, 6.26-6.6.35 for solar tent dried fish and 15.74-20.56, 6.32-6.41 for open sun dried fish. At the period of sensory rejection, total bacteria viable counts, Total Volatile Basic Nitrogen and pH were 5.7×106 cfu/g, 18.98 and 6.38, respectively, for open sun dried. On the other hand, solar tent dried fish registered 4.1×102 cfu/g total bacteria viable counts, 17.28 Total Volatile Basic Nitrogen and pH 6.33. Relatively higher levels of Esherichian coli, Salmonella, Vibrio and Micrococcus bacteria were detected in open sun dried compared to the solar tent dried fish. Protein range for solar tent dried and open sun dried samples were 63.3±0.15-61.09±0.07% and 63.3±0.34-58.19±0.21% respectively. Moisture content remained constant and significant (p= 0.001) at 8.3±0.12 and 17.0±0.01% for solar tent dried and open sun dried Diplotaxodon limnothrissa respectively. Visible fungal growth was observed from week 2 of storage in open sun dried fish and the isolates of Aspergillus 3.3×101 and Penicilium 3.3×101 were identified. The results confirmed the application of solar tent drying as an efficient technology for fish processing in Malawi. The study recommend use of solar tent drying to increase shelf life and safeguarding markets for value addition of small fish products in Malawi.