Free Amino Acids and Quaternary Ammonium Bases in Mantle Muscle of Squids

Abstract

Free amino acids and quaternary ammonium bases were analyzed in the mantle muscle extracts of eight species of the squids, such as Todarodes pacificus, Ommasterphes bartrami, Nototodarus sloani gouldi, N. sloani sloani, Illex argentinus, Loligo opalescens, Sepia esculenta, and S. pharaonis. Among the compounds analyzed, glycine, alanine, proline, arginine, octopine, taurine, trimethylamine oxide, and betaine were found in relatively large amounts in the muscles, but the distribution patterns of these compounds differed from species to species. The non-enzymatic browning of seasoned-dried foods prepared with the muscle of Ommastrephes bartrami has been said to be remarkable as compared to that of Todarodes pacificus, and it was assumed from this study that one of the causes is attributable to the abundance of arginine and glycine in the muscle of Ommastrephes bartrami.