Nearly half of the sushi purchased and DNA tested over a period of two years was mislabeled or misidentified, according to a recently published study. The Japanese style food was sold as a type of fish other than what it was claimed to be. The study, conducted by researchers from Loyola Marymount University and UCLA, discovered that fish ordered at Los Angeles sushi restaurants were mislabeled approximately 47 percent of the time.
ABC7 Los Angeles reported that the study analyzed the DNA from samples of sushi taken from LA restaurants between 2012 and 2015. Certain types of sushi made from varities of fish like tuna and salmon was labled correctly the most often, with salmon, for instance, correctly 90 percent of the time.
There were other types of sushi, though, that the researchers ordered during the study that they were always served a fish different than what was ordered. Two of the types of fish that were typically mislabeled were red snapper and halibut sushi.
The researchers ordered sushi claiming to be red snapper or halibut types a total of 75 times, and were given other species of fish every time. Another example was yellowfin tuna, which Grub Street reported that researchers found was not yellowfin tuna seven times out of nine orders.
They obtained similar results when they sampled high end grocery stores product over a one year period. The Daily Mail reported that when it came to high-end grocery stores in Los Angeles, fish was mislabeled 42 percent of the time.
During the four-year-long study, according to Grub Street, 364 sushi samples were taken by the researchers from the restaurants. They did not expect that 47 percent of the samples would be mislabeled, partly because they used Yelp and Zagat ratings to select the 26 spots their samples.
The team of researchers investigated 9 different types of fish, discovering all were mislabeled at least once. Besides the red snapper, yellowfin tuna, halibut, and salmon already mentioned, the researchers also ordered sushi that was labeled to be yellowtail, mackerel, alabacore, bigeye, and bluefin tuna.
The researchers who conducted the study and analyzed the DNA from sushi samples at LA restaurants believe that the restaurants were probably unaware that they have been serving customers mislabeled fish. The researchers think it is possible that somewhere along the way in the supply chain, a bait-and-switch of product may have occurred before the fish reach the point of sale and consumers.
UCLA professor and senior author of the study, Paul Barber, stated half of what consumers are buying is not what they think it is. He said that it is difficult to know where in the supply chain mislabeling begins, but added he suspects that the mislabeling in some cases is intentional.
When the study began, Barber said that he suspected he and his colleagues would discover some mislabeling, but he said he had not thought the levels would be as high as they found in some types of sushi. The researchers suggested that at least some of the mislabeling that happens is that the translation of names of fish caught in foreign lands may be wrong, or the mislabeling is intentionally done in the country of origin.
Grub Street reported that one of the co-authors of the study, Demian Willette, suggested to consumers that a generally safe bet, when ordering sushi, is to order salmon. Since it was mislabeled only 10 percent of the time, it was the safest bet to actually receive when ordering.
By John Samuels