Seasonal Variations of Free Amino Acids in the Muscle and Viscera of Small Abalone Haliotis diversicolor

Seasonal variation in the level of free amino acids was investigated in the muscle and viscera of cultured small abalone Haliotis diversicolor. Among free amino acids in the small abalone, the predominant one was taurine, followed by arginine, glycine, glutamic acid and alanine. The muscle contained higher amounts of total free amino acids, taurine, arginine, and glycine than the viscera, but the latter had more glutamic acid than the former. The levels of total free amino acids, taurine, and taste-active amino acids including arginine, glycine, glutamic acid, and alanine in the muscle of small abalone sampled from October to January were higher than those from other seasons. The result of free amino acid analysis was generally consistent with the fact that the small abalone was more tasty in the autumn and winter seasons.