Abstract
Free and combined amino acids in the ethanolic extracts of various spontaneous edible mushrooms were determined by liquid chromatography, prior to the determination of proteinaceous amino acids. The following results were obtained.
1. Total nitrogen in the extracts significantly differed in 28 specimens of spontaneous mushrooms subjected to the present study. They deviated in a range of several hundreds to 6, 000mg per 100g of dry fruiting bodies. Percentage of free amino acid nitrogen to total nitrogen was commonly under 30%. Mushrooms belonging to Tricholomataceae, Agaricaceae and Phylacteriaceae showed considerable superiority in the contents as 700 to 1, 600mg. Nitrogen in combined form was, on the other hand, less than that in free form, ranging from 20 to 400mg.
2. Total free amino acids in these mushrooms varied widely from 10 to 800μmol/g dry materials. In these mushrooms, alanine, glutamic acid, threonine and serine were found commonly to be containedin a high amount as free form. On the contrary, cystine, methionine, tyrosine, phenylalanine, histidine and arginine were significantly low in their levels.
3. Similarity of the pattern of free amino acids found to range within 0.80-0.99. The evidence suggests that the mutual similarity in the free amino acid patterns exists in the species subjected. Rather low similarities were observed, however, in several species, Laccaria laccata, Armillariella mellea, Lentinus edodes and Ramaria spp.
4. The amount of combined amino acid in ethanolic extracts of these mushrooms was less than 30% of the amount of free form, whereas several species were found to contain combined form equal to or more than that of free form. Glutamic acid was the most abundant as combined amino acid and aspartic acid and glycine were also commonly found.
