TG-FTIR analysis applied to the study of thermal behaviour of some edible mushrooms

The article is devoted to the study on the thermal behaviour of three species of edible mushrooms: Boletus edulis (foot and cap), Pleurotus ostreatus (foot and cap), Lactarius deterrimus (cap) by the TG-FTIR-coupled technique, in air, over the 30-900 A degrees C temperature range. The analysis of the TG-DTG-DTA curves reveals the thermal degradation mechanism to be complex and specific to every species under the recording conditions applied. A similar degradation mechanism is noticed for the foot and cap of Pleurotus ostreatus in comparison with the Boletus edulis and Lactarius deterrimus species where the mechanisms are different. The TG-FTIR analysis, combustion heats and IR spectra of the starting samples also support these results. The initial degradation temperatures from TG-DTG indicate the temperature range where these species are thermally stable and their nutrient features maintained making them proper for food. The TG-FTIR analysis gives information on the gaseous species evolved by the thermal degradation bringing thus a contribution to the elucidation of the changes developing by processing the edible mushrooms (industrialization, conservation, culinary preparations, etc.) at temperatures above the initial degradation temperature. At the same time, the environmental impact, when the mushroom failed cultures are burned, is also important.