The smell of food is one of the most important factors in assessing its quality. In this study, the influence of drying method on aroma/volatile compounds of oyster mushrooms (Pleurotus ostreatus Jacq.) was evaluated. The drying methods tested were convective drying (CD), freeze-drying (FD), vacuum microwave drying (VMD), and a combination of convective predrying and VM finish drying (CPD–VMFD). The volatile compounds were extracted by solid-phase microextraction and identified by gas chromatography–mass spectrometry. The best fitting model to describe the drying kinetics of the oyster mushroom was Henderson and Pabis model. Thirty-four volatiles in fresh oyster mushrooms were identified, with 3-octanone (2,890 µg/100 g dry basis) and 3-octanol (991 µg/100 g) being the major components. The total concentration of volatiles of fresh mushroom (4,506 µg/100 g) was drastically reduced by all drying treatments, although the highest contents were found after: (i) CPD (50°C)–VMFD (480 W) (245 µg/100 g) and (ii) VMD at 480 W (143 µg/100 g). According to the sensory data, the products dried using the treatment CPD (50°C)–VMFD (480 W) were those closer to the fresh mushrooms.

In the context of the growing demand for biomass, which is being encouraged by the EU directives on the promotion of the use of renewable energy, recent investigations have been increasingly focused on fast-growing energy crops. The aim of this study was to investigate the energy properties of three types of agricultural energy crops: Arundo donax L., Miscanthus × giganteus and Sida hermaphrodita. This investigation looked into the content of non-combustible and combustible matter, higher and lower heating values, lignocellulose content, and biomass macro-elements. The results indicate that the energy values of these crops are comparable, while their lignocellulose content shows significant variations. Thus, Arundo donax L. can best be utilised as solid biofuel due to its highest lignin content, while Miscanthus × giganteus and Sida hermaphrodita L. can be used for both liquid and solid biofuels production. As far as Arundo donax L. is concerned, a higher ash level should be taken into consideration.

Biomass obtained from cultivated energy crops is one of the raw materials with the highest potential in renewable energy production. Although such biomass can be used in production of lignocellulose bioethanol, it is currently mostly used as solid fuel for generating heat and/or electric energy via combustion processes. Calorific values, proximate and ultimate analysis, cell structure and micro- and macro-elements data are considered as basic parameters in the valorization of fuel properties during biomass combustion processes. Energy crops are cultivated with the aim to produce the largest possible quantity of biomass with minimal agro-technical inputs. One of these crops is Sida hermaphrodita (L.) Rusby. Given the fact that the chemical composition of biomass is influenced by a number of agro-ecological and agro-technical factors, the aim of this work was to determine the fuel properties of Sida hermaphrodita biomass obtained from three different harvest seasons (autumn, winter and spring) and cultivated in the area of the Republic of Croatia. On the basis of these investigations it was possible to conclude that harvest delaying towards spring season had a positive impact on suitability of using biomass of Sida hermaphrodita in the combustion process, which primarily means significant lowering the contents of moisture (18.64%), ash (1.94%), and nitrogen (0.65%), but also means increasing the contents of fixed carbon (6.21%) and lignin (25.45%).