walnuts
Walnuts are the fruit of the Juglas regia tree, belonging to the Juglandaceae family.
In the botanical sense, walnuts are drupes; these are oily seeds (edible portion) wrapped in a woody endocarp (the shell), in turn covered with a fleshy portion (called mallo, mesocarp and epicarp).
As for the nutritional aspect, being fleshy fruit seeds, walnuts are NOT cited in the classification of the VII basic food groups. The reason why walnuts are not classified within the aforementioned classification is to be found in the relative nutritional content. In fact they essentially yield lipids and fibers, with a few grams of protein. For this reason, they cannot be compared to other seeds (cereals and legumes, which instead contain mainly complex carbohydrates) and not even to fruits (which have the mesocarp as an edible portion, not the seed, and which supply mainly water and fructose). Walnuts are therefore quite different also from the other drupes used "commonly" in human nutrition; one of these is the olive, which has an edible portion characterized by the mesocarp and the epicarp (the opposite of the walnuts).
Walnuts can be eaten fresh, after simple extraction of the seed from the coatings, or even dried. An oil and flour are also extractable from the nuts which, of course, have quite different characteristics than those of cereal and legume flours. As far as the husk is concerned, as already mentioned, although edible is mainly used in the production of nocino; some work it by candying.
Walnut flour
Walnut flour is a product obtained by processing ripe seeds, extracted from the fruit, then shelled and finally dried. These are peeled and squeezed for the extraction of oil (a fairly prized product), while the fibrous residue forms the basis for walnut flour.
The gastronomic use of walnut flour is mainly the basic one or ingredient for the dough. Mixed with that of wheat (however never in considerable percentages, personally I would not exceed 10%) it gives rise to an alternative, extremely pleasant bread; in the same way it is applicable in the formulation of fresh pasta (up to 15%), even if in this case it is advisable to associate it with whole eggs or with egg whites (egg pasta), which allow to maintain a discreet holding of the dough to cooking (since the amount of gluten is relatively compromised). In the production of cakes, walnut flour allows to obtain leavened cakes with chemical yeast (eg walnut cake, which is GLUTEN FREE)! There is no shortage of recipes for various desserts (semifreddo, Bavarian, ice cream, etc.), while it is also interesting to add walnut flour to the appearance of crepes, as well as the structuring of various types of sweet or savory sauces (even with honey, walnuts, berries, chestnuts etc.).
Walnut flour is therefore marketed as such and sold pre-packaged. However, what needs to be taken into account is that this product represents a low-quality substitute compared to home-made walnut flour. The latter, rigorously integral, contains a lipidic dose that reaches 68%, while commercial nut flour is around 19% (since it is obtained from the residue of the oil extraction).
NB . To produce wholemeal walnut flour at home it is necessary to respect the same advices mentioned for hazelnut flour.
Containing good fatty acids (predominantly polyunsaturated omega 6, but omega 3 is not lacking), walnuts are consumed due to their high lipid content, which seems to boast a beneficial effect on the body (cholesterol reduction). Logically, for its part, commercial flour brings greater portions of fiber (despite the seeds being deprived of the surface film) and of proteins (having a minor biological value); remember that walnut flour is frequently used in the structuring of vegan recipes, with the aim of completing the biological value of proteins derived from cereals and legumes, or as a source of vitamin E, of essential fatty acids (omega 6 and omega 3), arginine (amino acid), antioxidants, phytosterols, tannins, etc.
Recall that walnut flour is a potentially allergenic food and that its consumption is to be avoided in early childhood nutrition. Moreover, while containing vit. And, it is an easily perishable food, which undergoes a lot of the oxidation of the polynature chains. This results in two negative aspects: the first is a poor conservability and the very rapid deterioration of the organoleptic-gustatory characteristics; the second is the reduction of nutritional properties due to the reduction in the vit. And antioxidant and polyunsaturated essential fatty acids. It is therefore advisable to keep walnut flour in the fridge (or freezer), preferably in vacuum-sealed containers and in containers that block the passage of light.
