A project that evaluated the efficiency of different chitosan treatments when used by fishery companies has now ended. The project was a cooperative effort by Primex, Rammi, Fjardarlax and Matís with a financial support from AVS (R&D Fund of the Ministry of Fisheries and Agriculture in Iceland).
The purpose of the project was to evaluate the efficiency of different chitosan treatments (A, B, C, D) when used by fishery companies, aiming to reduce seafood surface contamination and promote enhanced quality of fishery products: whole cod, shrimp and farmed salmon.
The alkaline conditions establishing in chilled raw shrimp during storage (0-1°C) is the probable cause for no benefits of chitosan treatments A and B used shortly after catch, except for the slower blackening of head and shell observed compared to the control group. On the other hand, salmon treatments C and D were most effective in significantly reducing skin bacterial load up to 6 days post-treatment (1.4°C) which inevitably contributed to the extended freshness period (by 4 days) and shelf life observed. Similarly, freshness extension and delayed bacterial growth on skin was evidenced after 6 days of storage in whole cod (-0.2°C) treated with solution D.
For cod stored at higher temperature (2-3°C) and processed into loins on days 3 and 6 post-treatment, a slower microbial deterioration was observed only during early storage of loins. The contribution of chitosan treatments to sensory quality enhancement was not clearly demonstrated in these products. Based on the findings, better chilling conditions should contribute to an enhanced effect of chitosan skin treatment towards quality maintenance.
For additional information please contact dr. Eyjolfur Reynisson at Matís.