Level of Synthetic Antioxidant in Cultured Fish and Fish Feed

DENG-FWU HWANG, JUI-HSING LIN AND HONG-MING CHENG

Department of Marine Food Science, National Taiwan Ocean University, Keelung, Taiwan, R.O.C.

ABSTRACT

   Attempts were made to determine the level of synthetic antioxidants and lipid quality in fish feeds and in cultured fish in Taiwan. Sixty eight samples of six fish species, thirty-seven feed samples for seven fish species and thirty-three samples of fish meal from six countries were collected from markets and/or from manufacturers, and analyzed. It was found that BHT (dibutylated hydroxytoluene) was the major antioxidant in cultured fish, fishery feed and fish meal. BHT level ranged 0-12.3 ppm, 0-59.8 ppm and 0-150.0 ppm in fish liver (or shrimp hepatopancreas), feed and fish meal, respectively. There was no residue of antioxidant in fish muscle. The lipid quality of fish feed was as follows : peroxide value (POV) 0.2- 60.8 meq/kg, thiobarbituric acid (TBA) value 6.4- 45.6 mg/kg and acid value (AV) 9.8 - 66.6 mg/g; and for fish meal POV was 5.6 - 85.6 meq/kg, TEA value 4.6-88.6 mg/kg and AV 6.2- 70.1 mg/g, There is no safety concern on the synthetic antioxidant residue in cultured fish, fish feed and fish meal. However, the lipid quality in fish feed and fish meal should be improved.

Key words:Antioxidants, BHT, cultured fish, feed.