The nutritional properties, advantages and differences between oily fish and white fish will be discussed. You probably already know that the properties of fish are very healthy. These nutritional properties vary depending on the characteristics of each fish. Fish is an essential component of a balanced diet and it is recommended to eat two to four portions of fish per week. In addition, at least one of these should be oily fish. But of all the fish species, can we distinguish between white fish and oily fish? Let's start with a list of fish from the family of white fish and oily fish:

• Examples of oily fish: anchovy, tuna, tuna, sardines, mackerel, mackerel, mackerel, mackerel, dogfish, horse mackerel, permit, swordfish, eel, eel, salmon, redfish, mackerel... (Full list of oily fish).
• Examples of white fish: John Dory, sea bream, perch, hake, sole, cod, scorpion fish, sea eel, turbot... (Full list of white fish).

Generally speaking, we can distinguish between oily and white fish based on the proportion of fat in their muscles (depending on the time of year, oily or white fish can be semi-fatty, as their body fat content varies). This brings us to the first difference. Let's look at them one by one:

Fat

The reason why some fish species accumulate more fat in their bodies than others is purely for survival: fish species that need more energy at certain stages of their life cycle, such as when they are forced to migrate for long periods, have more fat in their bodies. Oily fish travel long distances and need to build up fat in their muscles to do this. White fish do not need to travel because they find their food nearby, so they accumulate less fat. White fish have only 2% fat, oily fish 5-10%, but this is healthy fat. The fats provided by oily fish are unsaturated, including Omega 3 fatty acids, which are recommended for protecting the heart, lowering blood cholesterol and triglyceride levels, regulating blood pressure, preventing degenerative diseases... Omega 3 fatty acids are also considered to be a powerful anti-inflammatory. Our body does not produce these types of fatty acids, so they must be obtained from the diet.

Colour

The second difference is related to the first, as the amount of fat affects the colour (fat gives a blue tint, hence the name).

Where do you live?

Blue fish swim near the surface and white fish swim in layers near the bottom.

Farok

One way of physically distinguishing white fish from blue fish is the shape of the tail. Blue fish usually have an arrow-shaped tail, which helps them to travel long distances. White fish, on the other hand, have a straighter, flatter or rounded tail edge.

Nutritional properties

Both are rich in quality protein, minerals and vitamins, but there are some nutritional differences:

• Because white fish are lower in fat, they contain fewer calories than oily fish.
• However, the fats in fish are unsaturated fatty acids, especially Omega-3 fatty acids, so oily fish are richer in this treasure.
• As far as vitamins are concerned, because oily fish are oilier, oily fish are predominant in fat-soluble vitamins. In other words, they contain more vitamins D, E and A than white fish, which are rich in B-complex vitamins (very rich in B12).

Which one to choose? The ideal is undoubtedly diversity; this way we can take advantage of the qualities of all species. It is recommended that you eat at least four portions of fish a week, including at least two portions of oily fish, and in the case of cardiovascular problems, we would increase this to four. But remember that a good diet must be accompanied by other healthy habits and, of course, daily exercise. Enjoy your meal!

The difference between anchovies, Boquerón and Bocarte; a great topic of conversation, very common in front of a bar full of pintxos or in other contexts of gastronomic enjoyment. Same thing? No? What's the difference? Suffer no more doubts, we'll clear it up for you now. And the difference... is basically in the preparation! In fact, when we talk about anchovies, anchovies or anchovies, we are talking about the same species. It is true that depending on the area or region you are in, you tend to call them one way or another, but the most common thing is this:

• Anchovies: anchovies are called anchovies when they have been salted for a few months and take on their characteristic brown colour. They are then cleaned one by one and preserved in oil.
• Boquerón: this term is used when fish, once caught, are dipped in vinaigrette, which gives the loins their characteristic whitish colour.
• Bocarte: is so called when it is caught fresh and eaten fresh.

In fact, when we talk about anchovies, anchovies or anchovies, we are talking about the same species, whose scientific name is Engraulis. But you should know that not all anchovies are the same. Their scientific name is engraulis, and within this genus there are different species depending on the area in which they are caught. In this case, the second name changes, as does the quality of the meat. The first class anchovy is called Engraulis Encrasicholus and is found in the Mediterranean and the Cantabrian Sea. At Conservas Serrats, we use only the best quality spring anchovies, Engraulis Encrasicholus, fished in the Bay of Biscay, our beloved Bay of Biscay, and at its best between April and June, when it is at its peak in fat and flavour. With this jewel, we continue to make anchovy and anchovy preserves from Cantabria.

The main differences between longfin tuna and light tuna are described below. Many consumers confuse longfin tuna with tuna. Longfin tuna is the most select species of tuna. The most striking culinary difference is that the flesh is much tastier and the texture is exceptionally smooth. On the other hand, the colour of its flesh is much whiter than that of other tuna. Another advantage of longfin tuna is that it has a lower fat content: while light tuna has a fat content of 10%, longfin tuna has only 6%. Size is also an important difference between the two species: light tuna can weigh more than 50 kg, while adult longfin tuna rarely exceed 15 kg. Tuna is another medium-quality tuna species. Usually found in many canned products on the market, its flesh is pinker and less delicate than that of longfin tuna. Commercial names for tuna include yellowfin tuna or bonito tuna. This is the lowest category of tuna, as its flesh is darker and much coarser in texture. The term "tuna" covers different species of fish; some belong to the genus Thunnus and are considered to be the true tuna, but there are other species with similar characteristics that are also included in this group for various reasons. The nomenclature of tuna varies widely in different countries and regions of the world. In the following we will discuss the main distinguishing characteristics of the three most common tuna species:

LONGFIN TUNA

• Its scientific name is THUNNUS ALALUNGA, although it is also known as albacore tuna.
• This is the most valuable and rarest tuna.
• They range in size from 30 centimetres to one metre and weigh up to 10 kilograms.
• The dorsal part of its body is strongly blue, almost black, and the ventral part is whitish.
• It is easily recognised by its longer middle fin, which is more than two-thirds the length of the fish.

LOW TONES

• Scientific name THUNNUS ALBACARES.
• It is similar in size and appearance to the longfin tuna.
• The pectoral fins are much shorter than those of the longfin tuna, and the dorsal fins and belly are yellowish.
• It is the most fished tuna and therefore the most used for canning.

BLUEFIN TUNA OR RED TUNA

• Scientific name THUNNUS THYNNUS.
• The bluefin tuna stands out for its size.
• Raw meat is highly valued in Japan.
• Weights usually exceed 100 kg, and some specimens can weigh up to 600 kg.
• Some call it a "sea cow", while others compare its meat (if it is large and wild) to beef: red, fatty, spicy and tasty.
• Very voracious and excellent swimmers, they live in the Atlantic and Mediterranean seas.
• Bluefin tuna is fished particularly in May, June and July, when it is in its spawning season in the Mediterranean.

Examples of the most commonly found and consumed blue fish in the world:

• Anchovies or fresh anchovies.
• Eel
• Herring
• Tonhal
• Longfin tuna
• Mackerel
• Dogfish
• Bastard mackerel
• Lamprey
• Saurel
• Kardhal
• Salmon
• Redfish
• Sardinia

Knowing the varieties of blue fish is like having a map of the treasure trove of omega-3 fatty acids. A nutritional treasure that, in addition to regulating blood cholesterol levels and preventing cardiovascular disease, is crucial for some of the body's basic functions. In addition, blue fish have many other nutritional properties. Depending on the proportion of fat in their muscles, there are different types of fish: blue, semi-fatty and white. The blue fish gets its name from its colour. It does indeed undertake long journeys, which require it to build up fat in its muscles. This fat (the jewel in the crown) greatly influences the external colour of its skin. But remember that not all the blue fish on the list are the same. For example, the term "tuna" covers different types of fish (see our website for information on the main types of tuna and the differences between longfin tuna and light tuna); similarly, anchovies are not all the same (we also outline the differences between the different types of anchovy). In a nutshell, the blue fish on the list are high in nutritional value and there are many species to choose from. In Serrats we select the best quality fish and give you some recipes to help you get the most out of them.

Below is a list of the most commonly consumed white fish in the world.

• Cod
• Sea bream
• John Dory
• Hake
• Tengerimalac
• Unique
• Turbot