FISHERIES RESEARCH INSTITUTE,MOA,TAIWAN

Hard clams tend to have sands within its shells after harvest. These sands will be expelled when the clams are soaked in saline water. The sands could not be found any more in organoleptic sensory test when the clams were soaked in 10～30 ppt diluted sea-water for 2 hours, but the effects will not improve by increasing soaking times. On the contrary, if the salinity become too high or too low, the effect of expelling the sands by clams will be reduced. Moreover, salt content of hard clam meat will be influenced by the salinity of soaking water. When soaked in fresh-water for 2 hours, salt content remain the same as origin. When soaked in salinity of 5～15 ppt, salt content will reduced. But soaked in salinity more then 20 ppt, salt content will increase gradually. During soaking the hard clam in saline water, the content of total free amino acids in the meat will be decreased gradually as time past within 12 hours, except for taurine, alanine, glutamic acid, glycine and arginine. Hence we suggest the best soaking condition for hard clam is in 15 ppt of saline water for 2 hours.