Chestnuts - large-fruited/hybrid

Castanea sativa (edible chestnut) and its hybrids with Castanea crenata are large deciduous trees of the Fagaceae family. Botanically, they are monoecious, with prominent male catkins and inconspicuous female flowers. The fruit is an achene (chestnut) enclosed in a spiny cupule. While pure C. sativa excels in fruit quality, hybrids are bred mainly for resistance to fungal diseases (ink disease, bark cancer). Nutritionally, they differ significantly from other "nuts": they are low in fat but high in complex carbohydrates (starch), making them more similar to grains or potatoes. They are gluten-free and are the only nuts that contain significant amounts of vitamin C, along with potassium and B vitamins. Their phytochemical profile is rich in phenolic acids (gallic, ellagic) and tannins (concentrated in the thin shell of the kernel), which have strong antioxidant and astringent effects.