The Industrial Analysis Research Institute at Kumamoto University and Japan Seafoods Co., based in Fukuoka, Japan, have jointly developed a new method of killing anisakis parasites using pulsed electricity.
Anisakis is a nematode parasite with the appearance of a thin worm, which can enter the flesh of fish within its life-cycle. In Japan, where much fish is consumed raw as sashimi, anisakis poses a danger – when consumed, a living parasite can cause intense stomach pain.
Traditional methods of killing anisakis on fish are by cooking at 70 degrees Celsius or freezing at negative 20 degrees Celsius for 24 hours. However, freezing causes quality deterioration of the flesh and the product must be marked as thawed, lowering the value. A method for use on fresh fish has been desired.
On 22 June, 2021, the joint research team announced the completion of a prototype anisakis device that kills any parasites present in fish while maintaining the quality of sashimi. The machine, now installed at the Japan Seafoods Hakozaki Factory, passes 100 megawatts of pulsed electricity through a cold saltwater bath containing the fish. The power is released in bursts lasting only in the range of a nano-second to a micro-second.
“When the technology was applied to horse mackerel fillets containing 1,000 anisakis, all anisakis [are] killed, and we believe that the risk of food poisoning of anisakis can be significantly reduced,” The team said in a Kumamoto University press release. “In addition, this method enables treatment to kill the nematodes while maintaining the quality of fish sashimi, and is considered to be useful as an alternative to freezing.”
Kumamoto University Institute of Industrial Nanomaterials Professor Takao Namahira told SeafoodSource said the technology will be featured at upcoming seafood industry exhibitions.
“Sample shipment has already started,” Namahira said. “However, since the shipping volume is limited, we will refrain from making a large-scale announcement.”
The new invention still requires some improvement in cost and energy savings before it is ready for commercial use in mass processing, according to the press release. The prototype device only handles three kilograms of fish at a time, and it takes about six minutes to complete its process.
Photo courtesy of the Industrial Analysis Research Institute at Kumamoto University
