The blue fish category refers to anchovies, sardines, tuna, mackerel, herring, swordfish and longline. They are usually small fish, apart from tuna and swordfish, which can be up to three meters long. These fish are wrongly considered to be in the “B league” for fish: In fact, they contain a lot of poly-unsaturated fats and the famous omega-3, which can help to produce good cholesterol. They are also rich in proteins, vitamins and mineral salts, such as selenium, calcium, phosphorus and potassium. The fat present in blue fish is not harmful to our health because it is very different from beef, which clogs the arteries and causes cardiovascular disease. The fact that these fish live in the open sea is also a guarantee of healthiness, because they are far from the concentrations of pollutants that are absorbed by the fish that live along the coasts.
How to choose blue fish
To make sure the blue fish you’re selecting is fresh, it should have firm, smooth and tight skin. The gills should be bright red with a bright eye. The belly should be swollen and brightly colored. There must be no unpleasant odor and if it’s sliced, the skin should adhere well to the bones.
Blue fish in the kitchen
This type of fish has been part of Italian gastronomic culture for a long time. Some species are even present in ancient texts and have always been a fundamental ingredient of many traditional recipes – from the sardines in saor venete, to the sauce for Piedmontese bagna caoda and pasta with Sicilian sardines.
How to prepare blue fish
Tuna, which is the largest species (besides swordfish), is usually cut into slices and eaten as steaks. The smaller varieties of blue fish, such as sardines, anchovies or mackerel, are easy to cook and clean. For sardines and anchovies, a light pressure on the belly is often enough to open them, revealing the intestine and bones, which are easy to remove. An alternative method is to cut off the heads (when pulled slightly, this will also remove all the entrails). Steamed or baked are the best ways to cook the small blue fish, though anchovies, sardines and mackerel are often sold preserved in oil, smoked or fresh. They are also excellent barbecued or cooked in a pot with dried fruit and tomatoes. One way to keep them for a longer time is to put them in salt. (It is not rare to find tin boxes full of anchovies covered with coarse salt at the supermarket.) In this case, clean off the salt and rinse. Remove the entrails and finally season with some excellent quality extra-virgin olive oil, a clove of garlic, pepper and chopped parsley.