• Energy Research

Due to the need to diversify energy sources and transform the energy system and its decarbonization, new paths for obtaining raw materials are being sought. One of the potential options is to increase the use of grasses’ share in bioenergy production, which has a significant area potential. However, the diversified chemical composition of grasses and their anatomical heterogeneity mean that, between the various cultivars and species, the parameters determining their energetic usefulness may differ significantly, hence the key is to know the appropriate parameters at the variety level of a given species in order to effectively carry out the combustion process. In this experiment, a total of 23 varieties of seven grass species (Kentucky bluegrass (Poa pratensis L.), Red Fescue (Festuca rubra L.), Perennial Ryegrass (Lolium perenne L.), Meadow Fescue (Festuca pratensis Huds.), Timothy (Phleum pratense L.), Common Bent (Agrostis capillaris L.), Sheep Fescue (Festuca ovina L.), which had not yet been evaluated in terms of energy utilization, were tested. Proximate analysis showed the average ash content was in the range of 5.73–8.31%, the content of volatile matter in the range of 70.99–82.29% and the content of fixed carbon in the range of 5.96–17.19%. Higher heating value and lower heating value of grasses ranged from 16,548–18,616 kJ∙kg−1, 15,428–17,453 kJ∙kg−1, respectively. The Sheep Fescue turned out to be the most useful species for combustion. It has been shown that there may be statistically significant differences in the parameters determining their combustion suitability between the various varieties of a given species of grass. Therefore the major finding of this work shows that it is necessary to need to know theparameters of a given variety is necessary to optimize the combustion process and maintain the full energy efficiency of the system (especially lower heating value).

Prunus padus L., is not very popular plant, it is commonly found due to low soil requirements and easy to settle in various places. As for now, concerning food technology, there is no wide application for P. padus. Therefore, the aim of this study is to evaluate the possibility of using bird cherry bark as an ingredient in herbal functional teas. In the first step, the conditions for extraction of the bark were electrochemically optimized. It was proven that the highest content of polyphenols could be found in the sample consisting of chamomile, linden flower, and calendula (7939.8 ± 106.6 mg/100 g dm). In the beta-carotene bleaching test, the highest activity could be spotted for calendula tea (16.7 ± 1.1c%) and chamomile tea (15.0 ± 2.0c%) and concerning the test for linden flower tea without added bark (134.4 ± 15.1b μg ascorbic acid /mL). The property of the tested teas to inhibit cholinesterases was proven. What is more, P. padus bark infusion showed the highest activity of 15.8 ± 1.1d μg neostigmine/mL, for acetylcholinesterases (AChE) inhibition and 21.2 ± 1.0c μg neostigmine/mL for butyrylcholinesterases (BChE). The same tea also showed the highest activity to reduce ions of iron (Fe(III)): 25.3 ± 0.9c μg Trolox /mL and glutathione reductase and glutathione peroxidase inhibition, 87.0 ± 1.1e% and 64.9 ± 2.0d% respectively. The use of P. padus bark may be vital in the preventive care concerning modern-age diseases and allow for the production of a new range of products with distinctive sensory characteristics and functional properties and, at the same time, in combating the spread of P. padus in the farm and forest ecosystem.