Effect of Hypochlorous Acid on Oyster based on Dehydrogenase Activity

Abstract

Oysters have to be cleaned using sterilized seawater so that they may be eaten raw.We studied the effect of adding hypochlorous acid (HCIO) to sterilize the seawater on oysters. Oysters with shells and without shells were prepared. Half of them were kept in seawater containing 2 3μg/ml of Cl2, while the other half was kept in seawater without HCIO as the control. All changes were observed and the dehydrogenase activity on the oyster's gills for 5 days (with shells) and for 48 hours (without shells) was measured.In the seawater containing HClO, the gills of oysters with shells became loose after 3 days. Oysters without shells looked smaller due to the HClO after 24 hours. The dehydrogenase activity of the oysters in contact with the HClO, both with shells and without shells, decresased 70-90% compared to the control.Although the oysters were not killed by the 2 3μg/ml remaining Cl2, their gills were damaged. Since the gill's breathing helps oysters to be clean, the effect of clean up is thought to be reduced by the treatment.