Extractive Nitrogenous Components ot Cultured Milkfish and Tilapia

Abstract

The nitrogenous components extracted from the homogeneous fillets of cultured milkfish and tilapia were analyzed and compared. No difference in the profile of extractive components between dorsal and ventral part of milkfish was found, but the latter contained a higher quantity of these compounds than the former. There was a significant difference in the profile of free amino acids (FAA) between milkfish and tilapia. Histidine was the most prominent and accounted for about 80 % of the total FAA in milkfish. On the other hand, tilapia was rich in taurine and glycine, but contained a small amount of histidine. A similar profile of nucleotides and related components was found in both fish, and IMP was the most abundant compound. Both fish also contained a significant amount of creatine and certain levels of quaternary ammonium bases, such as trimethylamine oxide (TMAO), glycinebetaine and trigonelline. In general, milkfish extracts contained more FAA, creatinine and trigonelline, but had less nucleotides, creatine, TMAO, TMA and glycinebetaine than those of tilapia. The pattern of the extractive components of milkfish was found similar to that of red-fleshed fish, however, tilapia seemed to be analogous to whitefleshed fish. © 1990, The Japanese Society of Fisheries Science. All rights reserved.