Abstract:

The effects of chitosan coating on preservation of grass carp (Ctenopharyngodon idellus) fillet were studied in this experiment. Four chitosan based film were designed, treatment 1 (1.5% chitosan), treatment 2 (1.5% chitosan + onion ethanol extract), treatment 3 (1.5% chitosan + ginger ethanol extract), and treatment 4 (1.5% chitosan + garlic ethanol extract), taking distilled water as the control group. Fish fillet were dipped into the solution described above for 5 minute, and then stored in a refrigerator maintained at 8℃. Sensory evaluation, total bacterial counts, total volatile basic nitrogen (TVB-N) and pH of the fillet were determined at 0, 3, 6 day of the experiment. Sensory evaluation of all treatment groups were higher than that of the control group, but their bacterial counts, TVB-N and pH were all lower than those of the control group. Sensory evaluations of treatment 2 and 4 were higher than that of treatment 1, and their bacterial counts, TVB-N and pH were all lower than those of the treatment 1. Those results indicate that chitosan coating can inhabit the microbical growth and protein decomposition, and has a good ability to maintain the quality of fish fillet during storage; the extractions of onion and garlic have the antimicrobial ability and can increase the effectiveness of chitosan film in fresh-keeping