Fruit-flavoured amberjack are raised on feed that contains about 10 per cent of yuzu peel and juice. The feed raises the concentration of limonene, a substance responsible for the aroma of citrus fruit, to 20 times larger than the minimum level humans can smell. As of last December, at least 23 types of fruit fish had been cultivated in eight prefectures across Japan.
"If artificial farming techniques can help create more tasty fish, the value of cultured fish will rise and the fisheries industry will be revitalised," said Professor Fukada. "It would be great to see fruit fish being enjoyed by those who normally don't like seafood."
Other fish farmers in Japan are also throwing their hats into the ring. In Kagawa prefecture on the island of Shikoku, farmers are grinding olive tree leaves into a powder and mixing it into feed pellets given to hamachi or yellowtail. The fish are given the pellets for just over two weeks.
Olives add flavour, a high amount of Vitamin E and reduce any unpleasant odours. In Nagasaki prefecture, southern Japan, farmed mackerel are given nutmeg, oregano, cinnamon and ginger so their meat becomes more fragrant.
Fruit and herb flavoured fish are still only a small fraction of all farmed fish but producers hope that the distinct flavours and aromas of their products will draw attention at home and abroad.