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The process of extracting seleno-protein from the selenium enriched Lyophyllum decastes mycelia cultured in a 20 L fermentor was optimized, and the effects of selenium enrichment on both types and contents of amino acids in Lyophyllum decastes mycelia were analyzed. Single factor tests and Box-Benhnken central combined response surface test were used to optimize process of extracting seleno-protein from Lyophyllum decastes mycelia. The content of protein was determined by 3,3'-diaminobenzidine spectrophotometry. The types and contents of amino acids in mycelia protein before and after selenium enrichment were compared by means of amino acid analyzer. The results showed that the optimal conditions of extracting seleno-protein from mycelia of Lyophyllum decastes were extraction temperature of 64 ℃, extraction time of 60 min, liquid-solid ratio of 200:1 g/mL, and extraction times of 2. The protein extraction rate was 75.13%, and the content of selenium in mycelia was 63.87 μg/g. The amino acid composition were analyzed by means amino acid score (AAS) and chemical score (CS), and the nutritional value of the protein in the selenium-enriched Lyophyllum decastes mycelia was evaluated. The varieties of amino acids in the selenium-enriched Lyophyllum decastes mycelia were abundant and the content of essential amino acids for human body was 17.20 g/100 g, 19.75% higher than that in the non-selenium-ecriched Lyophyllum decastes mycelia. The ratio of EAA/NEAA was 0.51, close to the recommended value proposed by WHO, and the values of both AAS and CS were close to the those in the model protein. In summary, the protein extraction rate could be improved by optimizing the extraction process, and there was selenium in the protein from selenium-enriched mycelia, which promoted the increase of amino acid content. The nutritional value of protein in selenium-enriched mycelia was higher than that in non-selenium-riched mycelia, and selenium-enrichec mycelia had potential edible and application value.

In order to investigate the nutritional components and application value of Agaricus subfloccosus in the Qilian mountains. The amino acids, mineral elements, vitamins, protein, fat and carbohydrates of early-harvested (K type) and late-harvested (T type) were determined, and which were compared with Lentinus edodes, Agaricus bisporus and eggs. Based on the latest version of international amino acid reference patterns, amino acid score (AAS), ratio coefficient of amino acid (RC), IOM (Institute of Medicine) pattern score and chemical score (CS) were used to evaluated their nutrition value. The results showed that the fruitbody of Agaricus subfloccosus contained a considerable amount of nutrients, vitamins, mineral element and 16 free amino acids including 7 essential amino acids and 9 pharmacodynamic amino acids. The protein contents (32 and 29.2 g/100 g) of Agaricus subfloccosus (K type and T type) were more than twice of eggs, and the contents of mineral elements Zn (68, 45.3 mg/kg) and Se (0.262, 2.49 mg/kg) were higher, which were fit for the national standard, and the contents of total amino acids and total essential amino acids were higher than those of Lentinus edodes and eggs. The nutritional value of T-type protein was higher than that of K-type protein. The contents of 9 pharmacodynamic amino acids reached more than 62% of the total amino acids, the contents of delicious amino acids (f) and sweet amino acids (s) were rich, and the F/S ratio was more than 1.8, which was higher than that of Lentinus edodes and Agaricus bisporus. All the essential amino acids except methionine were accord with the internationally implemented amino acid balance model spectrum (AAS value higher than 125.25%, IOM model score higher than 105%, RC coefficient between 0.73~1.5, CS scoring coefficient better than that of eggs). In conclusion, Agaricus subfloccosus could be a delicious and high-quality edible and medicinal fungus. The results of this study would provide a scientific basis for further cultivation and promotion of Agaricus subfloccosus.