Chemical Constituents of Pleurotus ostreatus

Studies on Constituent of Edible Fungi Part II

Abstract

Pleurotus ostreatus (Fr.) Quel was divided into two groups, one was mature group with more than 1cm diameter pileus and the other was young group with less than 1cm diameter. The contents of water, ash, minerals, free fatty acids, organic acid, free amino acids and saccharides in pileus, stipe, and base of stipe were determined. The results are as follows: (1) Water and ash contents were from 86% to 92% and from 0.9% to 1.3% respectively for all of the parts examined. (2) K, P, Na, Mg, Cu, Zn and Mn were measured. The content of K (361mg/100g) was the highest, then P (121mg/100g), Na (28.0mg/100g) and Mg (17.4mg/100g) followed. (3) As for free fatty acids, C₁₄, C₁₅, C₁₆, C₁₇, C₁₈, C_18' and C_18" were detected. Among them C_18" was the main one which accounted for more then 60% of total fatty acid. (4) With ten prevalent organic acids, pyroglutamic acid was the largest, followed by malic acid and succinic acid. All of them were found to be higher in a stipe part. (5) The total free amino acid content was 337.4mg/100g in average. Twenty nine free amino acids were detected. Glutamic acid was the highest, followed by ornithine and alanine. These three amino acids accounted for about 35% of total free amino acid. Glutamic acid content was high in a mature pileus and in a base of stipe. Similarly ornitine and alanine contents were high in a stipe. (6) Mannitol was contained mainly in a base of stipe. In every part tested, mannitol was contained more than glucitol (7) Mannose and glucose were contained mainly in a stipe part.