PURPOSE: To enable the effective utilization of resources and the prevention of environmental pollution by mixing the soft part of shellfish or guts excluding the ligament with salt and a proteinase and subjecting the obtained liquefied product to boiling, squeezing, refining and concentration.

CONSTITUTION: The whole soft part of a raw or boiled shellfish such as scallop or the guts of the shellfish other than the ligament is mixed with salt and a proteinase and liquefied by fermenting and aging at 30-32°C for ≥3 days. The liquefied product is boiled, left standing to cool and squeezed to separate into liquid and residue. The liquid is separated and purified by a centrifugal separator and the purified product is concentrated to obtain the objective extract.