Effect of processing and storage methods on the shelf life and incidence of insect pests on smoked fish

Abstract

An experiment was conducted to determine the effect of proper handling, instant processing, different packaging materials (plastic containers with lids, high density polyethylene (HDP), paper cartons and aluminium foil) and storage methods (one set kept at 28-31C and another set packed in polyethylene and stored at 82C) on the shelf life and incidence of insect pests on smoked fish (Tilapia spp. and Clarias spp). The smoking chamber comprised of a metal bowl containing charcoal and wood cut into small pieces and supported with cement blocks. There was no insect infestation in fish samples processed in the laboratory but there were traces of moulds and fungi after 55 days packaging for those kept at 28-31C using all the packaging materials. On the other hand, those kept at 82C stored well without traces of moulds. The taste and smell of laboratory-processed Tilapia was good throughout the duration of storage and the texture of ground fish was brittle, except for those kept in HDP containers at 28-31C which became slightly mouldy and rancid with spongy texture at 55 days after packaging. Similarly, laboratory-processed Clarias exhibited good taste and smell throughout the storage period and brittle, except in those kept in HDP, carton and plastic containers which became rancid and spongy at 83 days after packaging. In the already smoked Clarias obtained from the market, infestation with Dermestes maculatus was observed at 10 days after packaging. Comparative data on the moisture content and pH of the processed samples are also tabulated.