Study of thermal behaviour of some edible mushrooms

This paper is aimed to analyse the thermal behaviour in air of edible mushrooms through nonisothermal (TG, DTG, DTA) and calorimetric (Berthelot calorimeter) methods. The studied mushrooms were Pleurotus ostreatus spontaneously grown and from culture and Agaricus bisporus from culture, currently used in alimentation but insufficiently investigated from this point of view. The analysis of TG-DTG-DTA curves has indicated that the degradation mechanism is complex and characteristic to every species and major differences between the cap and the stipe of investigated mushrooms have not been recorded. These species are thermally stable in the range of 30-160 A degrees C. The thermal stability in terms of initial degradation temperature (T (i) A degrees C) and the temperature corresponding to the conversion grade (T (alpha=0.03) A degrees C) indicate that the stipe has a thermal stability close to the cap one and that the cultivated mushrooms are more thermally stable than those spontaneously grown. The obtained results concerning the combustion of the sample using Berthelot calorimeter are in accordance with the TG-DTG-DTA analysis. The residue obtained is a measure of the mineral content and is quantitatively close.