Total Views: 387
Direct Research Journals
Direct Research Journal of Agriculture and Food Science:Vol.5 (6), pp. 263-267, June 2017
ISSN 2354-4147: International Standard Journal Number (ISJN) e-ISJN: A4372-2604

Microbial evaluation of Carica papaya leaf extract pre-treated smoke cured grass eater (Distichodus rostratus Gunther 1864)
Article Number: DRJA978460146

Original Research Article

Ebochuo V.C.1* and Oparaejiaku, J.2

1Department of Fisheries and Marine Technology, Imo State Polytechnic, Umuagwo, Ohaji, Nigeria.

2Department of Agriculture Management and Economics Technology, Imo State Polytechnic Umuagwo,Ohaji, Nigeria.

*Corresponding author E-mail:

date Received: May 7, 2017     date Accepted: June 16, 2017     date Published: June 23, 2017


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 0.80-1.80 kg were weighed eviscerated and washed properly with tap water. These were randomly divided into 4 groups of 3 fish each (T1, T2,T3 andT4). 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 85-95°C. 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 107 cfu/ml while T2= 2.2×105 cfu/ml, T3 =  1.5 x 105 cfu/ml and T4= 1.24 x 104 cfu/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 andT3) 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.

Key words: Microbial; Grass-eater; Evaluation; leaf-extract; Smoke-cured; Carica-papaya; Shelf life.