Effects of age on mineral elements, amino acids and fatty acids in Chinese chestnut fruits

Castanea mollissima BL (chestnut) is a kind of food with a unique flavor and high nutrition, which people pursue worldwide. As China is the birthplace of chestnut, there are many older chestnut trees all over the country. However, the nutritional value of the fruits of these old chestnut trees is not clear now. This study first assessed the nutritional value of old chestnut fruits (10 years, 100 years, 300 years, 500 years, 700 years and 900 years) in an old chestnut garden in Huairou, Beijing, highlighting the calcium, iron, zinc, selenium, amino acids and fatty acids. The age of all chestnut trees sampled was certified by Forestry Bureau of Beijing. These findings have revealed significant differences in the nutrient components of chestnuts with different years. The 10-year and 700-year groups have higher Zn, Se, and amino acid levels. Besides, the 700-year group has relative higher level of Ca and Fe and lower ratio of saturated fatty acid/unsaturated fatty acid. We also demonstrated that 700-year-old chestnuts have the highest nutrient value. This study provided a basis for establishing product quality standards for old chestnut trees and laid the foundation for further developing and protecting old chestnut in Beijing and even in the world.