Chapter 7 - Impact of Food Processing on Non-Hallucinogenic Indole Derivatives in Edible Mushrooms

Abstract

For thousands of years, the fruiting bodies of higher fungi have been used as a source of food. Edible mushrooms are increasingly being investigated because of their production of biologically active secondary metabolites. Qualitative and quantitative analyses of indole compounds in methanolic extracts from unprocessed and thermally processed fruiting bodies of selected edible mushroom species, belonging to the Basidiomycota taxon were performed. The methanol extracts from the unprocessed and processed mushrooms, after concentration in an evaporator, were purified by TLC preparative chromatography and then analyzed for indole compounds by the HPLC method. In all the extracts from mushrooms before and after thermal processing, several indole compounds with physiological activity were identified and quantified. On the basis of the analyses, the following indole compounds were found: l-tryptophan, 5-hydroxytryptophan, 5-methyltryptophan, tryptamine, 5-methyltryptamine, serotonin, indole, indoleacetic acid, indoleacetonitrile, melatonin, and kynurenine sulfate. The amounts ranged from 0.01 to 29.61mg/100g dry weight for raw mushrooms, and from 0.01 to 17.71 for heat-treated mushrooms.