The chestnut is the fruit of the chestnut. The term also designates the seed contained in this fruit and which is edible. Uncloisonne chestnuts are called chestnuts, not to be confused with horse chestnut, which is the poisonous seed of horse chestnut or common chestnut (Aesculus hippocastanum). The chestnut has long been the basis of human nutrition in entire regions. The chestnut tree was also called "the bread tree" but also "the sausage tree" because the chestnuts were also used to feed pigs.
The bug is the spiky envelope that protects the fruit. The different words for the chestnut in Europe all derive from the Latin Castanea.
A chestnut is formed from a thin, leathery, brown and shiny shell containing a seed. The shell is a pericarp with the three classic layers of the wall of a fruit: epicarp, mesocarp and endocarp. The chestnut detaches from the bug by its hilum. It has a protruding side from which emerges a small tuft called “torch” which is the dried-up remnant of the pistil and the five or seven floral “stigmas” and which protects the germ (plumule).
The seed is wrapped in a seed coat, a reddish and astringent film called the "tan" (because of the tannins it contains), which penetrates into the folds of the almond, and which must be removed before consuming the chestnut. . Varieties of chestnuts whose seed coat does not partition the almond are called chestnuts. The weight of the chestnut can vary from 10 to 25 grams depending on the variety.
Nutritional value
The chestnut, which is an achene, is formed of a floury mass wrapped in a smooth bark of reddish brown color called "tan". Chestnut can both designate certain improved varieties of chestnuts and horse chestnuts (chestnut seed found in cities). This can be confusing: be careful because the horse chestnut seed (horse chestnut) is toxic. We distinguish a chestnut from a horse chestnut thanks to their shape (the horse chestnut is generally larger and more rounded) and to the tail of the chestnut (the "torch") that is not found on a horse chestnut.
Chestnut cream and glazed chestnuts are made from certain varieties of chestnuts called chestnuts.
Fresh almonds contain up to 35% carbohydrates (starch, sucrose, dextrins), 5% fiber, but are poor in proteins (albumin) and lipids. It also contains vitamins, in particular vitamin C and mineral elements, in particular potassium. The sugar level of the fruit changes over time. It is usually more important a few weeks after harvest.
Chestnut flour contains more than 75% carbohydrates, which makes it an energy food.
Varieties
Many varieties are grown to meet the needs of confectionery or canning.
The essential choice criterion for buying a quality chestnut is above all its variety. The hybrid varieties, resulting from genetic crosses such as Bouche de Bétizac, Marigoule (M15), Bournette or Précoce Migoule give large and beautiful fruits but are, according to some, not the best.
Consumption patterns
Chestnuts can be eaten fresh or dried, raw (poorly digestible, they require effective chewing which promotes salivary impregnation and the action of salivary amylases which predigest starch), boiled, roasted, roasted in the oven, under the ashes or in perforated stoves. They are sold on the streets in winter with the cry of "Chauds les marrons!".