Changes in EPA and DHA levels during manufacture of dried fish and shellfish

Abstract

Horse mackeral (Trachurus japonicus), frog flounder (Pleuronichthys cornutus), Japanese whiting (Sillago japonica), hard clam (Meretrix lusoria), arkshell (Scapharca broughtoni), and scallop (Patinopecten yessoensis) were subjected to various drying processes to investigate the alteration of their eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) levels in each dried product. Dryings by hot drier, far infrared and microwave ovens were examined. On each sample, lipid content per unit increased, because water content of these decreased. But percentages of EPA and DHA in the lipids were not affected, and the peroxide value in case of drying by far infrared and microwave ovens did not impair the quality. These results suggest that dried products of fishes and shellfishes include more amounts of EPA and DHA than perishables. So these products should be rediscovered as effective functional foods for human health.