Dependence of anisakid larva inactivation by pulsed power on various parameters
Chinari Onitsuka, Kengo Nakamura, Douyan Wang, Mikiya Matsuda, Ritsuo Tanaka, Yoichi Inoue, Takao Namihira
Abstract
Anisakid nematode larvae are found in fish and cephalopods and causes anisakiasis when humans consume raw or undercooked seafood. The only practical way to kill anisakid nematode larvae apart from heating has been freezing, but killing them using electrical pulsed power technology is expected to be one of the ways, maintaining the quality of the raw fish meat. In order to inactivate the anisakid larvae more efficiently, this study examined various parameters of pulsed power that affect inactivation. The larvae of Anisakis pegreffii were embedded in horse mackerel fillets. The space between the treatment electrode was filled with saltwater with adjusted conductivity and fillets containing larvae were placed there, then the pulse current was repeatedly applied to inactivate the larvae. To investigate the effect on the immobilization ratio, the conductivity of the saltwater, the capacitance and charging voltage of the energy storage capacitor, the input energy into the treatment electrode, and the distance between the plane-to-plane electrode were varied. The difference in larva positions within the fillets and whole fish was also examined. Additionally, the salmons with the naturally infected larvae of A. simplex sensu stricto were used to confirm the inactivation. The results showed that the higher the input energy per pulse, the higher the inactivation effect, and that the position of the anisakid larvae within the fish also affected the immobility ratio.