Effect of gamma irradiation on the microbiological quality and shelf life of Engraulis encrasicolus in Ghana

The effect of irradiation on microbial load and shelf-life of anchovies (Engraulis encrasicolus) was assessed in this study. Irradiation doses used in the study were 2.5, 5.0, 7.5 and 10 kGy. The assessment was carried out at 3 weeks intervals for the period of 9 weeks. Samples were analyzed for microbial load (total viable count, total coliform count and Staphylococcus aureus). Smoked samples were more contaminated as compared to sun-dried samples from both locations. A dose dependent effect was observed in all the samples obtained from both Chorkor and Keta (p<0.05). Samples from Keta were less contaminated for both smoked and sundried samples as compared to the samples from Chorkor whether sun dried or smoked (p<0.05). At 2.5 kGy, microbial load levels (CFU/g) for total viable count, total coliform count and S. aureus were below the standard (CFU/g of microbial load) set by the Ghana Standards Authority for microbial load in fish. This dose is the most appropriate dose for the decontamination and shelf extension of anchovy from Ghana. Key words: Microbial load, processing methods, irradiation dose, shelf-life.