Changes in Chemical Compositions and Firmness of Salted Sea Urchin Gonads during Ripening

Abstract

hanges in chemical compositions and firmness of salted sea urchin gonads were investigated as a function of ripening time. The firmness of salted gonads increased for the first 14 days and then decreased unti1 30days. The viable cell count of fresh gonads decreased after the addition of sodium chloride and ethyl alcohol, and did not increase during ripening. During ripening for 180 days, total and reducing sugars, total nitrogen, volatile basic nitrogen and free amino acids in hot-water extracts increased by autolysis, which might contribute to the taste of salted and ripened gonads. Higher molecular weight proteins appeared in the initial stage of ripening and increased for 14days, and then they followed by a remarkable decrease. The polymerization of proteins was caused by the formation of cross-linking other than disulfide bond. The polymerized proteins may affect the firmness of salted gonads.