Composition of nutrients, heavy metals, polycyclic aromatic hydrocarbons and microbiological quality in processed small indigenous fish species from Ghana: Implications for food security

PLoS One. 2020 Nov 12;15(11):e0242086. doi: 10.1371/journal.pone.0242086. eCollection 2020.

Abstract

The triple burden of malnutrition is an incessant issue in low- and middle-income countries, and fish has the potential to mitigate this burden. In Ghana fish is a central part of the diet, but data on nutrients and contaminants in processed indigenous fish species, that are often eaten whole, are missing. Samples of smoked, dried or salted Engraulis encrasicolus (European anchovy), Brachydeuterus auritus (bigeye grunt), Sardinella aurita (round sardinella), Selene dorsalis (African moonfish), Sierrathrissa leonensis (West African (WA) pygmy herring) and Tilapia spp. (tilapia) were collected from five different regions in Ghana. Samples were analyzed for nutrients (crude protein, fat, fatty acids, several vitamins, minerals, and trace elements), microbiological quality (microbial loads of total colony counts, E. coli, coliforms, and Salmonella), and contaminants (PAH4 and heavy metals). Except for tilapia, the processed small fish species had the potential to significantly contribute to the nutrient intakes of vitamins, minerals, and essential fatty acids. High levels of iron, mercury and lead were detected in certain fish samples, which calls for further research and identification of anthropogenic sources along the value chains. The total cell counts in all samples were acceptable; Salmonella was not detected in any sample and E. coli only in one sample. However, high numbers of coliform bacteria were found. PAH4 in smoked samples reached high concentrations up to 1,300 μg/kg, but in contrast salted tilapia samples had a range of PAH4 concentration of 1 μg/kg to 24 μg/kg. This endpoint oriented study provides data for the nutritional value of small processed fish as food in Ghana and also provides information about potential food safety hazards. Future research is needed to determine potential sources of contamination along the value chains in different regions, identify critical points, and develop applicable mitigation strategies to improve the quality and safety of processed small fish in Ghana.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacteria / classification
  • Bacteria / isolation & purification
  • Fish Products / analysis*
  • Fish Products / classification
  • Food Contamination / analysis*
  • Food Microbiology
  • Food Security
  • Ghana
  • Iron / analysis
  • Lead / analysis
  • Mercury / analysis
  • Metals, Heavy / analysis*
  • Nutrients / analysis*
  • Polycyclic Aromatic Hydrocarbons / analysis*

Substances

  • Metals, Heavy
  • Polycyclic Aromatic Hydrocarbons
  • Lead
  • Iron
  • Mercury

Grants and funding

The here presented research activities were supported by funds of the Research Council of Norway and the Federal Ministry of Food and Agriculture (BMEL) based on a decision of the Parliament of the Federal Republic of Germany via the Federal Office for Agriculture and Food (BLE). The conducted work is part of the project “Small Fish and Food Security: Towards innovative integration of fish in African food systems to improve nutrition” (SmallFishFood) funded within the ERA-NET LEAP-Agri which was co-financed by the European Union´s EU Framework Programme for Research and Innovation Horizon 2020 under the ERA-NET-Cofund under Grant Agreement No. 727715. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.