Comparison of volatile compound production in fruit body and in mycelium of Pleurotus ostreatus identified by submerged and solid-state cultures.

Comparative analyses of the production of volatile compounds by Pleurotus ostreatus JMO.95 fruit body and its corresponding mycelium grown in liquid, on agar surface, and on solid support cultures were carried out by dynamic headspace concentration using gas chromatography/mass spectrometry and gas chromatography sniffing. The aroma produced by fruit body was owing essentially to the presence of octan-3-one and, to a lesser extent, to octan-3-ol. Other compounds, such as oct-1-en-3-ol, oct-1-en, 2-methylbutanol, and alpha-pinene were also present in low concentrations. Comparison of aromatic spectra of the fruit body with that of mycelia obtained under different culture conditions indicated that the main aromatic compounds present in the P. ostreatus fruit body and mycelium were produced in the same proportions on agar surface and on solid support culture, but not under submerged conditions.

Identification and quantification of Tuber melanosporum Vitt. sterols.

The sterol composition of Tuber melanosporum was examined by medium-pressure liquid and high-performance liquid chromatography, nuclear magnetic resonance spectroscopy, and mass spectrometry. Ergosterol (ergosta-5,7,22-trienol) and brassicasterol (ergosta-5,22-dienol) were identified as the major components (90%). Their quantities and their relative concentrations, probably good indicators for differentiating mature truffles from immature colored ones, were determined during the maturation of the fungus. The results show that the total quantity of sterols decreased with the age of the fungus, but that the ergosterol/brassicasterol ratio remained relatively constant.