Microbiological Quality of Traditionally Smoked Fish from Lake Victoria Crescent, Uganda

Rubaijaniza Abigaba ,Clovice Kankya ,Jessica L Nakavuma ,John David Kabasa

doi:10.7176/fsqm/104-05

Abstract

Microbiological quality of traditionally smoked fish was assessed to ascertain the effectiveness of traditional smoking process and handling conditions for smoked fish shelf-life and safety. Fish smoking is a popular preservation method in Uganda. Although fish smoking is a widely used method of preservation, the presence of spoilage and pathogenic bacteria in smoked fish and food borne illnesses remain a threat in developing countries. However, little is known about microbial quality of fish smoked from Uganda. In light of this, the status of spoilage, hygiene and pathogenic indicator organisms in fish (Nile perch) was investigated. A total of 75 randomly selected fresh, freshly smoked, and on shelf smoked fish from landing sites and markets respectively, were obtained for microbial and moisture content analysis. Descriptive statistics was used to present the data, while ANOVA and Tukey tests were used to analyze the data. The study revealed that, the smoking process significantly (P<0.05) reduced microbial load in freshly fish to levels acceptable for consumption, despite the high levels of moisture content in the range of 59.2% to 66.5%. The mean microbial load (log of cfu/g) of indicator organisms for samples from different sites varied from; 9.97 to 10.18; 7.39 to 8.19 (aerobic mesophilic bacteria or TPC), 5.18 to 5.27; 0 to 4.28 (total coliforms), 2.73 to 5.55; 0 to 0.85 ( E. coli ), 4.97 to 7.32; 0 to 3.11 ( S. aureus ), and 2.21 to 4.56; 0 to 0.82 (Yeasts and molds), for fresh and smoked fish samples respectively. Additionally, mean microbial load for on shelf smoked fish from markets varied from; 8.2 to 10.57 (TPC), 2.8-6.63 (total coliforms), 0 to 6.11 ( E. coli ), 6.74 to 8.89 ( S. aureus ), and 0 to 5.51 (Yeasts and molds). Although findings showed that, traditional fish smoking was somewhat effective in reducing microbial load to acceptable levels, the microbial status of on shelf smoked fish indicated poor fish handling and storage. Therefore, proper fish handling during and post-smoking as well as cooking before consumption, are highly recommended for assured shelf-life and safety of smoked fish for consumption in Uganda. Keywords: Microbiological, quality, smoked fish, Uganda, indicator organisms DOI: 10.7176/FSQM/104-05 Publication date: January 31 st 2021

Highlights

Fish is a valuable resource because it is a source of cheap proteins, long chain n3 polyunsaturated fatty acids (LCn3PUFAs), and foreign exchange (Kleter, 2004; FAO/WHO, 2011) especially in developing countries (Egbal et al, 2010)
Fish smoking is the most preferred preservation method, because it imparts a desirable flavor and inhibits microbial growth, and prolongs shelf-life of smoked fish (Kumolu-Johnson et al, 2009; Abolagba & Uwagbai, 2011). This method is the most widely used for preserving fish in Uganda, with Nile perch (Lates niloticus) and Tilapia fish species, being the frequently smoked by artisanal processors (Kabahenda et al, 2009; Abigaba et al, 2020)
Mean microbial load in fresh fish samples was highest for Kasenyi, followed by Ggaba, and Katosi landing sites

Summary

Introduction

Fish is a valuable resource because it is a source of cheap proteins, long chain n3 polyunsaturated fatty acids (LCn3PUFAs), and foreign exchange (Kleter, 2004; FAO/WHO, 2011) especially in developing countries (Egbal et al, 2010). This food commodity is highly perishable, a factor that greatly affects its shelf-life and consumer safety. Fish smoking is the most preferred preservation method, because it imparts a desirable flavor and inhibits microbial growth, and prolongs shelf-life of smoked fish (Kumolu-Johnson et al, 2009; Abolagba & Uwagbai, 2011). This method is the most widely used for preserving fish in Uganda, with Nile perch (Lates niloticus) and Tilapia (orechromis niloticus) fish species, being the frequently smoked by artisanal processors (Kabahenda et al, 2009; Abigaba et al, 2020)

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