Uwajima Project Inc., based in Uwajima City, Ehime Prefecture, Japan, has contracted with Sakai City, Osaka-based Kura Corporation – operators of Kura Sushi – to take trimmings, such as heads and bones, from the rotary sushi chain’s processing plant.
The trimmings will be dried and crushed and used along with fishmeal in aquaculture feed. The fish produced from the feed will in turn be sold to Kura Sushi.
Uwajima Project is mainly known for marketing farmed fish raised on feed that includes citrus oils, taking advantage of the peels of Mandarin oranges grown in Ehime Prefecture. The feed is claimed to reduce fishy odors and lessen discoloration.
Kura Corporation operates about 400 Kura Sushi shops nationwide. To supply these, it cuts up fish at its processing center in Kaizuka City, Osaka Prefecture, achieving a yield of about 60 percent and leaving the remaining 40 percent – about 600 metric tons a year – as processing waste.
Kouji Saiki, deputy director of the Kanto Division for Uwajima Project, told SeafoodSource that it currently has a contract to sell the fish produced by using the trimming in the feed only to Kura Sushi and do not plan to promote it to other customers. The types of fish are yellowtail, sea bream, and silver salmon.
The ocean water temperature in the area would normally be considered too warm for raising salmon, but Saiki said they are grown out in the winter when water temperatures are cooler. The salmon are harvested after only five months, at about 1.5 kilograms instead of the five kilograms typical for salmon from Chile.
The company’s motivations for reusing the processing scraps include the current high cost of fishmeal and pursuing the goal of conservation of resources.
