Seasonal variations in free amino acids, nucleotide-related compounds, and fatty acids and meat yield of the coconut crab Birgus latro

Abstract

This study analyzed seasonal variations in meat yield and compositions of free amino acids (FAA), nucleotide-related compounds (NRC), and fatty acids in muscle and hepatopancreas of the coconut crab Birgus latro of Okinawa, southwest Japan. A conspicuous increase in total meat yield was observed during September to November, prior to molting in the winter dry season. Although both total FAA and NRC content in muscle and hepatopancreas did not vary significantly by seasons, the taste activity value of methionine in muscle was larger than 1 only during September to November. Seasonal variations in equivalent umami concentration (EUC) were greater in muscle than in the hepatopancreas, with the EUC of muscles highest in September to November. Although fatty acid compositions of muscle and hepatopancreas did not change significantly seasonally, amounts of total fatty acids, saturated fatty acids, and monounsaturated fatty acids in muscle and hepatopancreas, and amount of n-3 polyunsaturated fatty acids in the hepatopancreas, were significantly greater in September to November. These results indicate the best season to eat coconut crab is September to November. These findings may contribute to a premium value for this resource and promote resource conservation of this species.