The chestnut belongs to the same family as the oak and beech. The four main species are commonly known as European, Chinese, Japanese and American chestnuts, some species called chinkapin or chinquapin.
Richly flavored, starchy, chestnuts are popular cool season edible nuts of the northern hemisphere. The nuts are native to hilly forest of China, Japan, Europe, and North America. Botanically they belong to the beech or Fagaceae family of the genus, Castenea. Scientific name: Castanea sativa.
Castaneas are very large deciduous trees. They are monoecious, bearing both male and female flowers in the same tree. They have a remarkable history to narrate. Early in the 20th century, the once mighty American-chestnut tree was mostly wiped out by pathogenic fungus chestnut blight. A renewed interest has been growing since then to revive native chestnut trees throughout of the USA.
Once pollinated, female flowers develop into large spiny burr or involucres, each enclosing about 2-3 edible kernels. The fruit is quite larger compared to its peers like cashews, macadamia, etc. Each nut features smooth, glossy dark-brown color outer shell, 1-1.5 inch in diameter and weighing 8-12 g depending up on the species. Inside they have a creamy white, sweet and starchy kernel.
Chestnuts, unlike other nuts and seeds, are relatively low in calories; contain less fat but are rich in minerals, vitamins and phyto-nutrients that benefit health.
Chestnuts are chiefly made of starch when compared to other seeds and nuts, which are high in calorie, protein, and fat. Their nutrition composition is almost similar to that of other staple starch foods such as sweet potato, sweet corn, potatoes, plantain, etc., Nevertheless; they are still good sources of minerals, vitamins and some good-quality protein.
They are a good source of dietary fiber; provide 8.1 g per 100 g. Fiber diet helps lower blood cholesterol levels by limiting excess cholesterol absorption in the intestines.
Chestnuts stand out from other nuts and seeds for their distinct nutrition profile. They are exceptionally rich in vitamin-C. 100 g nuts provide 43 mg of vitamin C. Vitamin C is essential for matrix formation in teeth, bones and blood vessels. Being a strong anti-oxidant, it offers protection from harmful free radicals.
Again, as in green-leafy vegetables, chestnuts are rich in folates, which is quite unique feature for nuts and seeds. 100 g nuts provide 62 µg of folates. Folic acid is required for the formation of red blood cells, DNA synthesis. Adequate consumption of food rich in folates during the peri-conception period helps prevent neural tube defects in the fetus.
They are rich source of mono-unsaturated fatty like oleic acid and palmitoleic acids. Studies suggest that monounsaturated fats (MUFs) in the diet help lower total as well as LDL (bad cholesterol) and increase HDL (good cholesterol) levels within the blood. Mediterranean diet which is rich in dietary-fiber, MUFs, omega fatty acids and antioxidants help prevent coronary artery disease and strokes by favoring healthy blood lipid profile.
The nuts are an excellent source of minerals such as iron, calcium, magnesium, manganese, phosphorus and zinc, besides providing a very good amount of potassium. Potassium helps counter hypertensive action of sodium, lowers heart rate and blood pressure. Iron helps prevent microcytic-anemia. Magnesium and phosphorus are important components of bone metabolism.
Further, they are also rich in many important B-complex groups of vitamins. 100 g of nuts provide 11% of niacin, 29% of pyridoxine (vitamin B-6), 100% of thiamin, and 12% of riboflavin.
Chestnuts, like hazelnuts and almonds, etc., are free in gluten. And for the same reason, they are one of the popular ingredients in the preparation of gluten-free food formulas for gluten-sensitive, wheat allergy, and celiac disease patients.
Chinese chestnuts are good in vitamin A; provide 202 IU per 100 g.
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