Microbial occurrence at different freezing duration in speckled shrimp, Metapenaeus monoceros (Fabricius, 1798) from local markets of Dhaka city

Abstract

A study was carried out at four different (0, 1, 7 and 30 days) freezing
durations in regard to the microbiological incidence in speckled shrimp
(Metapenaeus monoceros) from three different local markets - Ananda bazaar, New
Market and Polashi bazaar of Dhaka city. The study unveiled that Ananda
bazaar samples were more or less contaminated than those of others. The
microbial load varied with market sources as total bacteria count (TBC), total
coliform count (TCC) and faecal coliform count (FCC) were found in all the
storage periods crossing the acceptable limit. Except for E. coli (EC), all the
bacterial counts were significantly different (p < 0.05) in 7 and 30 days freezing
durations. A significant difference (p < 0.05) was found in all freezing durations
only for EC counts. After 30 days storage duration for all counts showed 101
cfu/g reduction of microbial load from every initial count. The Salmonella-Shigella
(SS) and Vibrio spp. were identified in all the samples of the three markets. In
case of biochemical composition, an inverse relation was found in moisture -
protein and moisture - fat where the moisture content increased after 30 days
freezing duration but protein and lipid contents decreased with time. This study
revealed that shrimp available in local markets of Dhaka city was highly ingested
with pathogenic bacteria which indicate the unhygienic condition of the market
premises.