Compositions of extractive components in the testes and ovaries of various sea urchins: comparisons among species, sexes, and maturational status

Abstract

We investigated the compositions of free amino acids (FAAs), organic acids (OAs), and nucleotides and their related compounds (NAs) in the gonads of edible sea urchins in Japan. In Hemicentrotus pulcherrimus and Pseudocentrotus depressus, glycine, alanine, lysine, and arginine were abundant FAAs in both sexes before gametogenesis. As gametogenesis proceeded, glycine and threonine showed increasing trends while arginine and histidine showed decreasing trends in both species regardless of sex. Alanine and serine in H. pulcherrimus and isoleucine in P. depressus showed increasing trends regardless of sex. Some other FAAs showed different trends between the sexes. Among the OAs and NAs, adenosine monophosphate, inosine monophosphate, and acetic acid were relatively abundant in H. pulcherrimus testes and ovaries before gametogenesis. In Heliocidaris crassispina, Strongylocentrotus intermedius, and Mesocentrotus nudus, glycine was commonly the most abundant FAA followed by alanine and arginine in the testes and ovaries during early gametogenesis. Compared to the other species, testes and ovaries of Tripneustes gratilla contained lower amounts of arginine and higher amounts of serine and proline. The results of this study could contribute to the development of the aquaculture and seafood industry for sea urchins by accounting for the variation in gonad taste among species, sexes, and according to their maturational status.