Microbial food safety of sun-dried and smoked European anchovies during nine months traditional storage in Ghana

Abstract

Storage of processed fish can improve food and nutrition security. But little is known about the microbial status or occurrence of mycotoxins during long-time storage of traditionally processed small fish for domestic markets. Fish processors from three different regions in Ghana processed anchovies (Engraulis encrasicolus) using two different smoking techniques (Chorkor and Ahotor oven) and two different sun-drying techniques (on the floor and on elevated racks), respectively, followed by traditional storage in paper-lined baskets. Samples directly after processing and after three, six, and nine months of storage were analysed for several microbial parameters and content of mycotoxins. Both smoking techniques resulted in lower numbers of total colony counts, moulds, coliforms and Clostridium spp. compared to both sun-drying procedures. Bacteria counts in samples of processed and stored anchovies were below national regulatory thresholds and were evaluated suitable for consumption from a microbiological safety standpoint. Aflatoxin B1 was not detected in any sample. Ochratoxin A was found in anchovies dried on elevated racks with increasing levels during storage. In conclusion, all tested preservation methods and storage environments in this study were able to produce anchovies of marketable quality. The presence of mycotoxins calls for further investigation to determine the risk for humans. Smoking resulted in lower bacterial counts compared to sun-drying. Bacterial counts did not increase during storage, while mould counts did increase. No aflatoxins were detected but ochratoxin A increased during storage.