Microbial Load (Bacteria, Coliform and Mould Count/Flora) of Some Common Hot Smoked Freshwater Fish Species Using Different Packaging Materials

Abstract

Three different packaging materials of (37 cm × 25 cm) size (Sealed Transparent Polythene Bag (STPB) Sealed Paper Bag (SPB) (Brown envelope), Open Mouth Polythene Bag (OMPB) (Black incolour)) were used for Oreochromisniloticus (O), Clariasgariepinus (C) and Mormyrusrume (M). Twenty fish samples per species (averaging 250 gm) were hot smoked dried whole for 36 hours at an average temperature of 100 ?C. Packaged hot at the rate of 6 fishes per package for each species (three packs for each packaging treatment i.e . 18 pieces were packed while the remaining 2 pieces were used for initial bacteria load and microbial load) . Microbial load (Total Viable Count (TVC), Total Coliform Count (TCC) and Total Fungi Count (TFC)) for the fresh fish was initial hot smoked and finally at the end of 12 weeks was monitored. The TVC (bacterial load) of O. niloticus dropped from (10.6 - 8.4) × 10 4 (fresh state-hot smoked) and M. rume (9.8 - 7.0) × 10 4 , while C. gariepinus slightly increased from (12.4 - 12.6) × 10 4 . After hot smoking, highest TVC of 8.6 × 10 4 (OMPBC), 8.3 × 10 4 (SPBC) and 8.2 × 10 4 (STPBC) were recorded in C. gariepinus among the 9 packag - ing at 12 weeks. However highest tendency for heavy TVC is in all OMPB with highest bacteria load in the OMPBC (8.6 × 10 4 ), 7.6 × 10 4 (OMPBO) and 6.6 × 10 4 (OMPBM). After 12 weeks highest ranged TFC of (0.6 - 0.7) × 10 4 was recorded in M. rume as against 0.2 × 10 4 recorded in the initial smoked for all. TCC was highest in C. gariepinus (4.0 - 4.3) × 10 4 . Packaging did not limit the existence of micro-organisms. Six bacteria species ( Micrococcus ( acidiophilus , luteus ), Bacillus ( subtilis , cereus , aureus ), Staphylococcus aureus , Streptococcus lactis , Proteus ( vulgaricus , morganii ), Pseudomonas aureginosa ) and three fungi species ( Aspergillus ( niger , tamari ), Rhizopusnigricans , fusariumoxysporum ) were represented in all the packages. On the average five bacteria and two fungi species were represented, excepting for OMPBM and OMPBO with six bacteria species .