γ-Irradiated Chitosan From Carcinoscorpius rotundicauda (Latreille, 1802) Improves the Shelf Life of Refrigerated Aquatic Products

This study evaluated the effects of γ-irradiated horseshoe crab chitosan coating on extending the shelf-life of selected high commercial value seafood. Fourier transform infrared spectroscopy (FTIR), Field-Emission Scanning Electron Microscopes (FE-SEM), X-ray diffraction (XRD) were used to characterize the γ-irradiated chitosan. Shelf life of the seafood samples was investigated via pH, thiobarbituric acid reactive substance (TBARS), total viable counts (TVC) and sensory evaluation. Seafood samples tested were shrimp (Penaeus merguiensis), pomfret (Pampus argenteus) and hilsa fish (Tenualosa ilisha). The shelf-life of experiment was using one control group (untreated seafood samples/no preservatives), chemical preservation (treated with 2% glacial acetic acid) and of 2% chitosan preservation solutions (0, 10 and 20kGy γ-irradiation). The shelf-life of selected seafood samples were observed over 15 days of storage at 4 °C. FT-IR, XRD and FE-SEM Analysis revealed significant changes in the structure of irradiated chitosan, mainly changes in functional groups which a crystalline and smoother surface structure. Analysis of pH, TBARS, TVC and sensory evaluation revealed that irradiated chitosan delayed microbial growth and prolonged the shelf-life of tested seafood samples.With the novelty that horseshoe crab chitosan actively preserves packaged products in fisheries industries, practitioners are assured that processed aquatic products are safe and free from microbial contamination during long-term refrigeration.