What are Seafood
With the term seafood we mean a group of foods of animal origin, often of salt water (but it is not said!), Which groups the organisms belonging to the vein of molluscs and to that of crustaceans.
Seafood - molluscs : cephalopods (provided with an internal shell or without a shell, such as octopus, cuttlefish, squid, octopus, squid, octopus, etc.); gastropods (univalve or with external shell, for example snails, snails, limpets, sea ears etc.); lamellibranchs (bivalves therefore with external shell, for example mussels (mussels), clams, fasolari, telline, canolicchi, scallops, canestrelli, sea truffles, sea dates, oysters, pinna nobilis, etc).
Seafood - crustaceans : macruri (long abdomen, lying down with a fan-shaped codal fin, for example lobster, lobster, prawn, scampi, etc.); brachiuri (short abdomen without fan, folded under the capotorace, for example the crab or the spider crab); stomatopods (provided with two buccal appendages with annexed "gullet" claws formed by a toothed movable article that folds over the segment itself (eg canocchia, corbola etc.).
Nutritional properties
To describe the nutritional properties of shellfish it would be advisable to treat the various animal species individually or, to the limit, the various classification groups; however, due to the heterogeneity typical of seafood-based preparations, the reader will benefit more from a general and less thorough description of the topic. Below we will analyze separately the two strands, namely the molluscs and the crustaceans.
The caloric content of molluscs is generally low or moderate; among cephalopods, gastropods and lamellibranches, the nutritionally richest ones are certainly the gastropods (snails, limpets, sea ears, snails, etc.), although less consumed and generally considered "obsolete" foods. They boast a higher energy and protein intake than the other two (around 100kcal per 100g and over 17g of protein, against 60-75 kcal and 10-14g of protein), which are widely used in low-calorie diets. We also remember that ALL molluscs (and especially cephalopods) contain an extremely reduced lipid portion and consist mainly of polyunsaturated fatty acids; on the other hand, the bivalves (especially mussels and oysters) are distinguished by a noticeable intake of cholesterol, an extremely limiting characteristic when correlated with cholesterol lowering diets.
The molluscs also provide good vitamin quantities of cobalamin (vitamin B12) and, in a variable manner, of the other vitamins of the complex B. They are also distinguished by a significant contribution of iron (Fe) emic, iodine (I), zinc (Zn) and selenium (Se). It is however advisable to pay attention to sodium (Na), as both bivalve molluscs and gastropods provide sufficient quantities to make them unsuitable for the dietary treatment of arterial hypertension.
It is not possible to uniquely describe the digestibility of molluscs, as it varies significantly from one group to another, from one species to another and, above all, from one culinary preparation to another; its shelf life is extremely limited, especially with regard to bivalves.
Analyzing the nutritional content of crustaceans in seafood, it is first of all appropriate to specify that these are ALWAYS foods with a high cholesterol intake, therefore, as for some molluscs, their use does NOT find frequent application in diets aimed at controlling the hypercholesterolemia. On the other hand, crustaceans have a moderate lipid content and are characterized by the prevalence of essential omega3 fatty acids compared to omega6, a characteristic that is undoubtedly appreciable. From the energy point of view, they rarely exceed 70-80 kcal per 100g of edible part, while the protein intake is good and is between 13 and 18g (the glucidic content is negligible).
Even the crustaceans in the preparation of seafood, like some molluscs (see above), contain a significant amount of food sodium and similarly are not indicated in hypotensive diets. However, they bring excellent amounts of iron and calcium (Ca), but with a reduced content of phosphorus (P), a mineral that at high doses becomes responsible for the impairment of intestinal calcium absorption. The content of B vitamins is similar to that of meat and fish.
Consumption frequencies
From what emerged in the previous paragraphs, the suitability for consumption of seafood depends exclusively on the presence of an adequate clinical picture. Hypertension and hypercholesterolemia are pathologies that make it difficult to include seafood in the diet, except for some of them (cephalopod molluscs); therefore, in these cases it is generally NOT RECOMMENDED for use (admitted occasionally by some and in limited quantities). At the same time, in the absence of metabolic alterations, the consumption of seafood could be useful in reducing the consumption of meat, eggs and cheese, BUT it must not replace in any way the consumption of the fish proper.
In a balanced diet, the consumption of seafood is hardly included in the weekly menu and in my opinion they could be used correctly once (1:10 or 1:15 days). In the case in which they were part of the eating habits of the subject, it would be desirable to prefer the varieties with lower cholesterol content and lower sodium content, as well as, if necessary, eliminate the cooking water of the foods with the aim of drastically reducing the TYPICAL residual sodium intake of seafood-based preparations.
Bibliography:
- Edible animals of the Italian seas - A. Palombi, M. Santarelli - pag pag 364
- Food composition tables - INRAN (National Food Research and Nutrition Institute)
- Food Microbiology - JM Jay, MJ Loaessner, DA Golden - Springer - 126-127
