양식 넙치용 습사료의 친환경적 개선을 위한 키토산 코팅제의 개발

Abstract

Most aquacultural farms have been using moist pellet (MP) feeds for growing cultured fish. However MP feds have severalserious problems, because of weak bind capacity of MP fed itself, including rapid colapse of the formation in salt water, fedloss, frequent ocurence of pathogenic fish diseases and environmental pollution. In order to overcome this situation in thefarms we tried to coat MP feeds with natural biopolymer solutions to enhance binding capacity of MP feds. Chitosan was themost efective biopolymer which improved suppresion rate of collapse in salt water and floating rate of MP feeds on the surfaceof salt water. In addition chitosan-agar complexed bipolymer increased the coating eficiency by about 50% in suppression rateof MP feed colapse in salt water, compared to non-coated MP feeds. Besides coating MP feeds with chitosan-based biopolymerprotected the growth of pathogenic fish bacteria such as vibrio spp., Edwardia tarda and streptococcus spp. separated fromJapanese flounder fish and increased oxidation stability against rancidity of the feeds during five days of storage. From theresults chitosan-based biopolymer might be an efective coating material for environmental-friendly improvement of fish MPfeds in aquacultural farms.