Functionality testing of selected Chill ‐ on technologies during a transport ‐ simulation study of palletized cod boxes: qPCR for fish spoilage bacteria, SLP model and QMRA to evaluate pathogen growth in spiked cod
In this study, tests were carried out on technical solutions developed in the EU project Chill ‐ on, where a simulation experiment was set up to simulate the actual transport of fish from Iceland to Europe. The temperature fluctuations experienced by the fish were aimed at mimicking transport from Iceland to France by ship. Pallets of cod fillets in foam plastic boxes were transported to the Westman Islands by ship and back to Matís in Reykjavík. Samples from these pallets were then compared with control samples that had been stored in Matís' refrigerated conditions. Cod nuggets were also packed in consumer packs (trays) immediately after processing and then after 6 days and were stored in subcooled or refrigerated conditions. Microbial growth experiments were also performed in which Listeria monocytogenes, Escherichia coli and Salmonella Dublin were added to cod necks stored in foam boxes in conditions similar to the storage and transport processes during export. Temperature measurements, sensory evaluation, microbial and chemical measurements were used to present data to test and verify the QMRA / SLP models and quantification of Pseudomonas bacteria using qPCR technology.
The aim of the cod wet trials and the corresponding shelf life study was to include scenarios to test and demonstrate the functionality of some Chill ‐ on technologies in a simulated cod supply chain. Temperature fluctuations were induced according to the actual scenario in the supply chain of cod from Iceland to France via sea freight. The study included sample groups created at the point of processing after packaging in EPS boxes. The reference group was stored at Matís under superchilled conditions. Simulation trials for downward distribution were performed at Matís upon receipt of the pallets shipped to the Westman Isles from Reykjavik (Iceland ‐ Europe freight simulation) and compared with the reference group. Repackaging of loins in retail trays was performed on days 0 and 6 with storage under superchilled and chilled conditions, respectively. In addition, a pathogen challenge trial was performed by spiking loins (5 kg) with Listeria monocytogenes, Escherichia coli and Salmonella Dublin, followed by storage in EPS boxes under temperature conditions simulating export and distribution. Temperature recordings along with microbial, chemical and sensory analyzes from the groups evaluated provided necessary data to test and validate the QMRA / SLP models and the quantitative molecular (qPCR) method to estimate counts of pseudomonads.