by Chef Jorge Sanchez, MBA
Sushi is a popular dining experience. Sushi is a Japanese term which refers to the little oval pillows of seasoned rice under a strip of raw fish. The raw fish without the rice is called sashimi, with perhaps the most popular sashimi being tuna. Species of tuna vary, some varieties like the bluefin are at a premium and sell for hundreds of dollars per pound. In the Keys, I’ve noticed the blackfin variety is often caught, so I wondered if these are just as safe to eat uncooked, as sashimi?
As a professional chef and educator, I am concerned for the safety of our food supply and try to convey to my students responsible procurement practices, sustainability, as well as high quality and flavor. I love the fresh, firm, dark flesh of sashimi tuna. I love the simplicity of not cooking the fish and serving it with a sweetened soy sauce or teriyaki, or even as a component in salsa. Chefs that use great ingredients should practice a philosophy of minimal manipulation of their food. A balance of sweet, salty, and a touch of acid, like lime juice or rice vinegar, is simple and delicious. But what about potential parasites and dangerous chemicals, such as mercury, in the Keys tuna supply?
I asked some of my academic colleagues, the marine scientist at FKCC, about this subject. They are some of the foremost authorities in the country on marine environmental engineering and technology. They enlightened me that tuna are largely pelagic or highly migratory species which are able to swim thousands of miles all over the ocean, to many different locations. Usually it is just by chance or by season that they have been caught here versus another locale. They are considered warm-blooded fish which give them a natural resistance to parasitic organisms and make them safe to eat raw. Other cold-blooded bottom feeding fish have the potential to host external parasites and should be cooked to insure all unhealthy organisms are destroyed prior to consumption. They should not pose a concern in our diet with proper preparation.
There have also been reports over the years of dangerous mercury levels in tuna and abstinence, especially pregnant women, should be practiced. My associates say much of this concern is overblown and perhaps a bit of propaganda from competing food industries to gain a competitive advantage. This may be also rooted in a concern of the natural process known as the biomagnification chain. This is where smaller fish with traces of mercury are eaten in large quantities by larger fish, and they in turn are eaten by even larger more predatory species, and so on, magnifying the presence of mercury via assentation of the food chain. Scientists see tuna as having minimal exposure to biomagnification, but do warn us as pollution in our waters increase, that the risk of healthy predatory fish like sharks and swordfish may be heightened. According to them, eating raw tuna in the Keys remains safe to eat, even when pregnant. Rapid reproduction, high population, and relative low demand also classify them as a sustainable food source.
Island Tuna Sashimi Salsa
- 1 lb Freshly caught blackfin tuna, diced small
- ¼ cup Seasoned rice wine vinegar
- 3 T Soy sauce
- ¼ cup Agave nectar
- 1 Lime, juiced
- 1 Garlic clove, mashed and minced
- ½ Shallot, minced
- ¼ Red bell pepper, seeded and diced small
- ¼ Small cucumber, peeled, seeded and diced small
- ½ Mango, diced small
- ¼ Avocado, diced small
- 1 T Pine nuts (optional)
- 2 T Fresh cilantro, chopped, stems removed
- 2 T Fresh mint, chopped, stems removed
- 2 Dashes pepper sauce
- Salt to taste
METHOD OF PREPARATION:
- Combine all ingredients, except the tuna, in a non-aluminum bowl and mix together.
- Let mixture stand for 30 min.
- Remove and reserve 1 tablespoon of the contents, set aside.
- Add diced tuna and toss.
- Drain excess liquid and carefully spoon mixture onto a platter or in a ring mold.
- Top with the reserved mixture
- Serve with tortilla chips and lime wedges