Abstract: The main nutritional components, amino acids and minerals in two samples of Xerocomus spadiceus from Linzhi city of Tibet were analyzed, and their nutritional values were evaluated in comparison with those of other boletus such as Boletus edulis, B. aereus and B. speciosus as well as Leccinum crocipodium. The results showed that proteins and crude fibers were the predominant components of X. spadiceus, with a total content of 43.29% and its crude fiber content was 13.73%, which was higher than that of other boletus species and Leccinum crocipodium. X. spadiceus had lower crude fat content with an average of 4.55%. In addition, X. spadiceus possessed a well-balanced amino acid composition with a ratio of essential to total amino acids of 39.10% and a ratio of essential to non-essential amino acids of 0.64, and with umamitaste and medicinal amino acids accounting respectively for 31.80% and 59.33% of the total amino acids. Glutamic acid, aspartic acid, alanine and leucine were the dominant amino acids in X. spadiceus. Methionine and cysteine were the first limiting amino acids. X. spadiceus was rich in minerals, especially potassium, calcium, iron, zinc, and selenium. Moreover, the contents of calcium and selenium in X. spadiceus were higher than in other tested mushrooms. Mercury and lead were not detected and the levels of cadmium and arsenic in X. spadiceus were within the range stipulated in the national standard of China. Therefore, X. spadiceus is a wild edible mushroom high in dietary fiber and protein, low in fat, and rich minerals.

Key words: Xerocomus spadiceus, nutritional evaluation, amino acid, minerals