FISHERIES RESEARCH INSTITUTE,MOA,TAIWAN

The freshwater clam was collected from the aquacultural farm in Sou Fon area of Haulien Prefecture. The extractive was extracted by steaming, or boiling, or boiling under pressure. The resulted extracts were further concentrated and dried. Effects of the size of clam, concentration and drying methods on the yield, glycogen and free amino acid contents of the extractive powder were investigated to evaluate feasibility of the production of clam extractive. The size of clam did not affect the production of its extractive, while the yield, glycogen and free amino acid contents increased with the increase in extraction times. According to the results obtained in this study, most of the free amino acids and glycogen were extracted after three times of extraction. Heating concentration was superior to the reverse osmotic concentration in terms of the yield of free amino acids. There were no toxic mercury and cadmium detected in the raw freshwater clam muscle. The concentration of these two metal in the highly concentrated extractive powder was less than 0.5 ppm which was beyond the limited value of FDA, ROC. As comparing with commercial products, extractive obtained from frehwater clam having higher concentration of free amino acid and glycogen contents suggested the high feasibility in the utilization of local freshwater clam for the processing of extractive. Key words: Freshwater clam extractive powder, Processing