An Investigation of cold chain management system breaches during exportation on the quality and shelf life of fresh fish

Chilling fish involves establishing and maintaining consistent chilled storage (cold chain) of between 0 and 2 °C using a combination of ice and refrigeration. This process offers logistical advantages to fish producers, maintaining a high quality for longer during distribution. Megrim (Lepidorhombus whiffiagonis) and pollack (Pollachius pollachius) are typically caught in Irish waters, with the majority of each catch (approximately 90%) exported to Europe. As part of this research and to ensure high quality exports from Ireland to continental Europe, temperatures were assessed and breaches during the distribution of whole chilled fish were identified. To better understand the effect of temperature on product quality these breaches were replicated under controlled laboratory conditions, where both species were evaluated to determine the resultant changes in fish quality and microbial growth. Samples were analysed using proximate composition, microbial analysis, colour, texture, total volatile basic nitrogen (TVB-N), and sensory analysis. Both species had low microbial counts on day 1 of storage, this gradually increased over time, as spoilage occurred. It was observed that when fish samples were stored outside of optimum conditions (0-2 °C), the rate of spoilage increased, with unacceptable microbial level thresholds exceeded in within two days. Similar results were encountered for both species across all other quality testing parameters (colour, texture, TVB-N and sensory), however proximate composition was not significantly affected. In conclusion, the main findings of this study suggest that temperature breaches can easily occur throughout the cold chain, drastically reducing the shelf life and quality of fish. Once fish was exposed to temperatures outside of the recommended (0-2 °C) for chilled fish, quality was severely degraded.