To optimize a method for preparing highly palatable grilled fish in a steam convection oven, fillets of mackerel were soaked for 10 s in one of four seasoning liquids (cooking sake, salt solution, sugar solution, or grain vinegar), then cooked under the same conditions in a steam convection oven. The grilled mackerel was then evaluated in terms of appearance, texture, taste characteristics, and palatability.
Component measurement results revealed that ash and salt contents were highest in mackerel soaked in the salt solution, followed by that prepared in cooking sake, reflecting the high sodium content of these two liquids. The Brix value of mackerel soaked in the sugar solution was significantly elevated, and the pH value of mackerel soaked in grain vinegar was significantly reduced. Sensory evaluation results showed that overall preference correlated strongly with aftertaste (+), moistness (+), and sourness (-). Mackerel soaked in sugar or salt solution or in cooking sake was favorably assessed with significant frequency, whereas that soaked in grain vinegar was unfavorably assessed with significant frequency. These results suggest that soaking in sugar solution and cooking sake, and seasoned with a little salt will result in grilled fish with high palatability.