Poisoning effects by alkali metal chlorides is one of the major reasons for the deactivation of SCR catalyst in biomass-fired plants. In this study, the influence of KCl on two vanadium-based catalysts with different promoters, V₂O₅-WO₃/TiO₂ and V₂O₅-Ce(SO₄)₂/TiO₂, was investigated. The catalytic activity of the fresh V₂O₅-WO₃/TiO₂ was higher than that of V₂O₅-Ce(SO₄)₂/TiO₂ at low temperatures. V₂O₅-Ce(SO₄)₂/TiO₂ performed better than V₂O₅-WO₃/TiO₂ when KCl was deposited on the catalyst surface. Both poisoned catalysts were efficiently regenerated by SO₂ treatment. The characterization results show that the reducibility and acidity of the catalysts were weakened by KCl deposition but regenerated by SO₂.

Valorization of winery waste is a promising solution for waste management with additional benefit of bioactive compounds isolation. The aim of this study was to analyze the nutritional and bioactive potential of oil derived from Serbian autochthonous grape seed variety Prokupac and to compare it with known international grape varieties. Additionally, two extraction methods (ultrasound assisted extraction and cold pressing) were used in order to determine their influence on physico-chemical and nutritive characteristics of grape seed oil. Different methods, including determination of physicochemical properties, content of bioactive compounds, oxidative stability and antioxidative capacity were used for the characterization of grape seed oils. Results indicated that the higher yield was obtained by ultrasound assisted extraction compared to cold pressing. The application of ultrasound assisted extraction resulted in increased α-tocopherol content and better antioxidant capacity and oxidative stability of oil. Significant differences in bioactive composition were observed for Prokupac seed oil compared to the other grape varieties. Oil extracted from Prokupac grape seed had the lowest content of polyunsaturated and the highest content of saturated fatty acids, the highest content of α-tocopherol and consequently, the best antioxidative capacity. Prokupac grape seed has a great potential for isolation of nutritive and bioactive valuable oil.

Agricultural waste originating from the wine industry presents an environmental and economic issue. Grape seeds, a major constituent of grape pomace, are only partially valorized through oil extraction. The cake remaining after oil production is rich in valuable bioactive compounds. In this study, an advanced extraction technique, which utilizes subcritical water, was employed for bioactive compound recovery from defatted grape seed cakes. Extraction was performed in a nitrogen atmosphere (10 bar) at 130 °C and 170 °C. The extracts were characterized in terms of the total polyphenols, flavonoids, proteins and antioxidant activity. Detailed polyphenol profiles were determined using UHPLC Q-ToF MS analysis. Quantification of the individual sugars was performed by HPLC. The amino acid profile was determined using ion chromatography. The yield of phenolic acids was found to be higher at 170 °C (883 vs. 557 mg/100 g at 130 °C), while the flavonoid content was favored at 130 °C (596 vs. 185 mg/100 g at 170 °C). The total protein, essential amino acid and xylo-oligosaccharide content was higher at 170 °C. The obtained results show that the use of water as the extraction solvent in subcritical conditions is a promising technique for the environmentally friendly valorization of grape seed cakes and biowaste in general.

Cold-pressed grape seed oil contains many bioactive compounds and its production enables the valorization of grape seeds as a by-product of winemaking. However, the incorporation of oils into food is associated with losses of active compounds and incompatibilities with the complex food matrix. Encapsulation is considered a process that could overcome these obstacles and enable a more diverse use of plant oils in the food sector. In this study, we developed an improved encapsulation process, submerged-nozzle dispersion (SND). SND aims at the encapsulation of active ingredients using highly viscous carrier materials. We used SND for the encapsulation of cold-pressed grape seed oil in alginate. The alginate stabilized the emulsions and provided stable conditions for the formation of encapsulates. The dried encapsulates were in the form of elongated particles with an average width below 150 μm; the oil content in encapsulates reached above 80% and encapsulation efficiency was up to 90%, depending on the formulation. Encapsulates exhibited satisfactory mechanical properties, suggesting they could mix well with other food ingredients. The SND encapsulation process developed in this study could be successfully applied to the encapsulation and protection of cold-pressed plant oils to be used as a source of valuable nutrients in foods.

Two different ways of extracting antioxidative compounds (including soluble polyphenols) from rusks made from wheat flour with added millet (Panicum miliaceum L.) were compared, i.e., solvent extraction and in vitro digestion. Wheat flour was replaced by millet flour in amounts of 10, 20 or 30 wt. % (per dry mass). Solvent extraction was realized using a mixture of ethanol and water in different percentages, with or without the addition of formic acid. The total content of phenolic compounds (TPC) was determined using Folin? ?Ciocalteu reagent, while the antioxidative capacity was measured by the DPPH (2,2-diphenyl-1-picrylhydrazyl) assay. The efficiency of solvent extraction was enhanced by the addition of formic acid. The addition of millet flour in amounts up to 20 % enhanced the antioxidative properties. It was shown that in vitro digestion was more efficient in the extraction of antioxidative compounds, in comparison with solvent extraction.