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Waste wood (biomass) is one of the most valuable and multifunctional environmental, long term resources of Earth. The aim of this paper was to study the possibilities for obtaining pellets from Juniperus. excelsa M. Bieb. biomass by a single-screw extrusion pre-treatment method. Biomass obtained after aqueous distillation of J. excelsa was used. The sample was grounded and sieved into dp ⩽ 500 μm and dp ⩽ 500 μm particle in size. The experiments were carried out on a single-screw laboratory extruder “Brabender 20 DN”. According to our results, the pellets with dp < 500 μm particle size were characterized with the following indicators: the mass flow rate (1.92 kg/h), sectional expansion index (1.03), specific mechanical energy (215.65 kJ/kg), density of the extrudates (0.44 g/cm3) and volumetric flow rate (4337.58 cm3/h). The samples obtained with dp > 500 μm particle size showed the following characteristics: the mass flow rate (1.30 kg/h), sectional expansion index (1.09), specific mechanical energy (535.23 kJ/kg), density of extrudates (0.48 g/cm3) and volumetric flow rate (2719.78 cm3/h). The biomass was a potential source for biofuel production. Pellets produced from biomass with a particle size dp > 500 μm had a higher density and sectional expansion index than those with a particle size dp ⩽ 500 μm. However, their production was more economically impractical, which is due to their lower mass and volumetric flow rate, as well as higher specific mechanical energy.

Cape gooseberry (Physalis peruviana L.), an exotic fruit gaining popularity in Bulgaria, has been recognized as a highly functional food, but has also the potential to be a resource for the fragrance and cosmetic industries. The main objective of this study was to assess the potential of the resinoid (a type of traditional aromatic products) obtained from locally-produced fruit (variety “Plovdiv”) for use in cosmetics, by revealing its volatile composition and characterizing the properties of an author-developed resinoid- enriched cosmetic cream. The resinoid (yield 58.78% DW) was a dark-orange viscous mass, with fruity, caramel notes and smoke accords odor. The GC-MS analysis identified 44 volatiles (98.69%), representing carbohydrates, alcohols, acids, along with minor miscellaneous compounds. A cosmetic cream (O/W emulsion) was developed, incorporating fruit resinoid (1.00%) as an active ingredient, compared to a control sample. Resinoid inclusion affected positively the sensory and physico-chemical properties of the cosmetic cream (color, odor, pH, stability). The studied emulsions had the rheological behavior of pseudoplastic non-Newtonian fluids, and resinoid presence reduced cream viscosity. It could be concluded that Cape gooseberry fruit resinoid had the potential to be a reasonable ingredient in cosmetic preparations; of course, further research is needed to assess its complex effects.

The moisture sorption capacity of tobacco seeds is decisive for their safe long-term storage; therefore, the analysis of the sorption isotherms, in a wide temperature and water activity range, is essential for seed quality maintenance in storage. In this study, the equilibrium sorption isotherms of tobacco (N. tabacum L.) seeds, “Kroumovgrad 90” variety of Oriental tobacco, were determined. The experimental data were obtained by the static gravimetric method at different temperatures and water activities. Sorption isotherms showed a typical Type II sigmoidal profile, with a significant hysteresis effect and a decrease of seed sorption capacity with the increase of temperature. The best fitting with tobacco seed sorption isotherms were the modified Chung-Pfost (desorption) and Oswin (adsorption) models. The monolayer moisture content, important for the safe storage of tobacco seeds, was also determined. The outcomes from the study might be of practical use in tobacco seed conditioning and storage design.