Effects of Salt Concentration and Composition on Sand Removal in Bivalves

Abstract

The effects of saltwater concentration and edible salt composition on depuration were examined in Manila clams (Ruditapes philippinarum). Moreover, the effects of saltwater concentration on depuration and taste-active compounds were evaluated in brackish water clams (Corbicula japonica). Manila clams displayed enhanced depuration in 1.5% and 3% saltwater(concentrations close to those measured in seawater). Edible salt solutions containing bittern components other than NaCl significantly increased siphon emergence and tended to enhance sand removal efficiency. Furthermore, Mg and Ca supplementation promoted siphon emergence. Sand removal from brackish water clams was the most intense at ≤0.5% NaCl, i.e., concentrations close to those of their natural habitat. The immersion of clams in NaCl solution suppressed amino and organic acid loss. These results indicate that 1.5% and 3% saltwater concentrations are effective for depuration in Manila clams, while 0.5% saltwater content is effective both for depuration and taste-active compound retention in brackish water clams.