Effect of konjac glucomannan and chitosan-based film coatings on the quality of fresh sea bass (Lateolabrax maculatus) under refrigerated condition

Sea bass (Lateolabrax maculatus) is one of the important seafood in China. Its shelf-life under refrigerated storage exponentially deteriorate due to the growth of spoilage microorganisms, protein degradation and lipid oxidation. In this study, 4 coating materials namely, konjac glucomannan-whey protein isolate (KGM-WPI) film, chitosan-sweet potato starch (CHI-SPS) film, chitosan-bamboo fungus (CHI-BF) film, and chitosan-boehmite alumina (CHI-BAH) have been explored to enhance the shelf life of sea bass during 8 days of refrigerated storage. Overall, CHI-BF was observed to be best in retaining hardness, gumminess and maintaining total volatile basic nitrogen value. Whereas CHI-SPS was found to retain chewiness and maintain lower values for drip loss and peroxide value. CHI-BAH coating was observed to maintain the lower values for pH and EC values of sea bass under refrigerated storage. However, the least increase in total viable count and minimum change in b* value was observed in the case of sea bass coated with KGM-WPI. The current research findings provide a new practical storage method for the entire fresh fish. The fresh fish can be coated with different coating materials and store on the ice at 4°C without packaging during retailing. These film coated whole fresh fish retains its microbial and sensory quality.