Abstract
Analysis of free amino acids, free sugars and sugar alcohols, organic acids and 5′-guanylic acid as well as a sensory evaluation were carried out to obtain basic nutritional data on the mushroom Pleurotus eryngii var. tuoliensis (Basidiomycetes). The free amino acid composition of freeze-dried samples in decreasing order was arginine, glutamic acid, aspartic acid, alanine and histidine. Functional amino acids ornithine, gamma-aminobutyric acid and citrulline were detected. The main free sugar and sugar alcohol was trehalose. The trehalose content was high and was found to be a characteristic taste component of the variety. Malic acid, fumaric acid and succinic acid comprised ≥80% of the organic acids. Investigation of changes in taste components following rehydration, which is a necessary step when using dried mushrooms in heated dishes, showed an increase in free amino acids following rehydration and almost no changes with subsequent heating. Conversely, 5′-guanylic acid increased with heating, and the increases tended to be greater for mushrooms soaked at lower temperatures. Hydrophobic amino acids produced in the rehydration process are hypothesized to be a factor affecting bitterness and palatability in sensory evaluations.
