Microbial Evaluation of Carica papaya Leaf Extract Pre-Treated Smoke cured Grass Eater (Distichodus rostratus Gunther 1864)
Ebochuo V.C. & Oparaejiaku, J.
Department of Fisheries and Marine Technology,Imo State Polytechnic, Umuagwo, Ohaji
Department of Agriculture Management and Economics Technology, Imo State Polytechnic, Umuagwo,
Email: victorebochuo@gmail.com
Corresponding Author: Ebochuo V. C.
ABSTRACT
The sensory and microbial evaluation of Carica papaya leaf extract pre-treated smoke cured Distichodus rostratus (Grass eater) was studied. Twelve (12) fish samples weighing between 0.80kg-1.80kg were weighed eviscerated and washed properly with tap water. These were randomly divided into 4 groups of 3 fish each (T1, T2, T3 &T4). T1 was immersed into 3% Brine only. T2 was immersed in a mixture of 3% brine and 2.5% C. papaya leaf extract. ). T3 was immersed into 3% Brine and 5% C. papaya leaf extract. T4 was immersed into 3% Brine and 8% C. papaya leaf extract. These mixtures were thoroughly mixed and allowed to stand for three hours. Soaked samples were poured out on muslin clothing for draining and cured with wood smoke on a brick kiln for four hours at a temperature range of 850C-950C. The cured samples were left overnight to cool and were wrapped in sterile polythene bags and kept in a refrigerator for microbial analysis. The samples were subjected to microbial analysis, culturing, incubating, colony count and statistical analysis. Increasing concentrations of water extract of C. papaya leaf inhibited microbial growth at all dilutions (highest T1{control} was 2.6 x 107cfu/ml while T2= 2.2×105cfu/ml,T3= 1.5 x 105cfu/ml and T4= 1.24 x 104cfu/ml ,decreased in that order). Probable organisms in T1 were Staphylococcus aures. T2 and T3 had Proteus sp.T4 had Klebsiella sp. Biochemical characterisation of pure culture isolates confirmed the presence of these organisms. The fungi found were Aspergillus (T1), Penicillum (T2 &T3) and Mucor (T4). These results show that usage of C. papaya in processing and preservation of fish will improve the shelf life of stored fish.
Keywords: Microbial; Grass-eater; Evaluation; leaf-extract; Smoke-cured; Carica-papaya; Shelf life.
