Tuna flakes are shavings from dehydrated, fermented, and smoked tuna. Cat owners often serve the fish flakes as a special treat or add them to cat food. Sometimes referred to generically as bonito flakes, the product may also be manufactured from the bonito fish, which is an ocean species related to tuna. Though cats savor the aroma and flavor of the fish, pets may develop health problems from consistent diets containing tuna. Tuna flakes are part of traditional Japanese cuisine and are frequently used as a garnish on hot dishes.
Once caught and returned to shore, the skipjack tuna undergoes a lengthy process before becoming tuna flakes. Processors generally remove the fins, head and organs of the fish and cut the body into fillets. These are arranged in a basket and placed in boiling water for about one hour. The water temperature remains constant at 194 degrees Fahrenheit (90 degrees Celsius). Following this cooking process, workers remove the bones, fat and scales from the tender fish.
The tuna undergoes a smoking process one or more times. The fillets are exposed to the smoke of castanopsis, oak, or pasania wood. After smoking for the desired length of time, processors shave the surface of the fish, removing dirt, tar and other debris. The fish are dehydrated further by placing the fillets directly into sunlight. Manufacturers extract additional moisture from the tuna by spraying them with mold spores.
The mold naturally depletes the fish of moisture as it grows. After substantial growth occurs, plant employees shave the surface, removing the mold. Workers generally repeat this process until there is no longer any moisture to support mold growth. At this point, the fillets have a consistency of hard wood. At roughly one-fifth its original size, the tuna now contains approximately 2% moisture.
Machines then remove layer after layer of paper-thin shavings from the tuna. Manufacturers package the tuna flakes and sell them all over the world. Pet owners generally find tuna flakes in specialty stores selling pet food and other products. The nutritional value of tuna flakes includes a minimum of 75% protein, 3% fat and 1% fiber. Some products may also be fortified with taurine, an essential cat nutrient.
Provided as an occasional treat, tuna flakes are relatively harmless. Diets consisting largely of tuna lack vitamins E and K. The absence of vitamin E causes a condition known as steatitis, or yellow fat disease. A lack of vitamin K prevents normal blood clotting. Tuna also contains elevated levels of magnesium which can contribute to bladder or kidney stones.