Selenium (Se) biofortification of aromatic plants is a promising strategy to produce valuable functional food with high biological activity and enhanced essential oil yield. The experiment carried out in 2021 and 2022 on A. annua treated with sodium selenate or nano-Se sprayed on foliar apparatus demonstrated a significant increase in photosynthetic pigments, pectin, waxes, macro- and microelements and a decrease in malonic dialdehyde (MDA) accumulation. Contrary to literature reports, neither selenate nor nano-Se showed a beneficial effect on essential oil accumulation; the oil yield did not differ between the selenate treated and control plants but was halved by the nano-Se application. Extremely high variations in the number of essential oil components, as well as in the eucalyptol, artemisia ketone, camphor and germacrene D ratio in the 2021 and 2022 experiments were recorded. The analysis of the 2016–2022 data for oil yield and composition in the control plants revealed a direct correlation between the number of components and of solar flares, and a negative correlation between oil yield and the percentage of spotless days. Both control plants and plants fortified with selenium showed higher levels of germacrene D and lower levels of artemisia ketone in 2022, characterized by more remarkable solar activity compared to 2021. Nano-Se supply resulted in the highest percentage of germacrene D accumulation. The results of the present research highlight the importance of the solar activity effect on the essential oil yield and quality of aromatic plants.

Biochemical and mineral peculiarities of plants inhabiting desert and semi-desert areas may provide important information about the mechanism of their adaptability and reveal the prospects of their utilization. Rheum tataricum L., known for its high tolerance to drought, salinity, and nutritional deficiency, is the least studied species of wild rhubarb. Using biochemical and ICP-MS analysis, the antioxidant status and mineral composition of R. tataricum were determined. Extremely high levels of antioxidant activity (148–155 mg GAE g⁻¹ d.w.), polyphenols (24.6–25.1 mg GAE g⁻¹ d.w.) and carotenoids (1.94 mg-eq β-carotene g⁻¹ d.w.) were revealed in roots, proline in leaves (71.1 ± 6.2 mg kg⁻¹ d.w.) and malic acid in stems (3.40 ± 0.50 mg g⁻¹ d.w.). Compared to garden rhubarb, R. tataricum demonstrated significant root–leaves translocation of Li, Se, Si, and Mo, known to participate in plant antioxidant defense. Under high levels of Ca, Na, Mg, Fe, Cr and Si in soil, R. tataricum demonstrated the ability to significantly increase the accumulation of these elements in roots, showing a hyperaccumulation ability for Sr. The first broad picture of R. tataricum biochemical and mineral characteristics in semi-desert habitat and its nutritional value indicate the prospects of R. tataricum utilization in plant breeding, medicine, and nutrition.

The complex evaluation of varietal biochemical differences in rhubarb juice, pomace and roots is highly useful to develop an efficient processing technology. Research was carried out to compare four rhubarb cultivars (Malakhit, Krupnochereshkovy, Upryamets and Zaryanka) in terms of the quality and antioxidant parameters of juice, pomace and roots. The laboratory analyses showed a high juice yield (75–82%) with a relatively high content of ascorbic acid (125–164 mg L⁻¹) and other organic acids (16–21 g L⁻¹). Citric, oxalic and succinic acids accounted for 98% of the total acids amount. The juice of the cultivar Upryamets demonstrated high levels of the natural preservatives sorbic (36.2 mg L⁻¹) and benzoic acids (11.7 mg L⁻¹), which are highly valuable in juice production. The juice pomace proved to be an excellent source of pectin and dietary fiber, whose concentrations reached 21–24% and 59–64%, respectively. The total antioxidant activity decreased according to the following sequence: root pulp (161–232 mg GAE g⁻¹ d.w.) > root peel (115–170 mg GAE g⁻¹ d.w.) > juice pomace (28.3–34.4 mg GAE g⁻¹ d.w.) > juice (4.4–7.6 mg GAE g⁻¹ f.w.), suggesting that root pulp is a highly valuable antioxidant source. The results of this research highlight the interesting prospects of the complex rhubarb plant processing for the production of juice, containing a wide spectrum of organic acids and natural stabilizers (sorbic and benzoic acids), dietary fiber and pectin (juice pomace) and natural antioxidants (roots).

The high biological activity of cultivated and wild purslane offers broad possibilities for utilizing this plant in medicine and human nutrition. To assess the prospects of obtaining new functional food products based on the wild form of P. oleracea L., foliar biofortification of this species with sodium selenate (VI) was carried out, and the changes in leaf and seed biochemical characteristics were investigated. Selenium significantly enhanced plant yield, photosynthetic pigments and the ascorbic acid content, and showed a tendency to seed productivity increase. The application of selenium augmented quinic acid content in leaves by 1.7 times but did not affect the oxalic acid content. Oxalic acid prevailed in wild purslane and quinic acid in cultivated purslane (cv. Makovey). Seed oil in Se-enriched purslane was characterized by a two-fold decrease in saturated fatty acids and squalene and 2.3-fold decrease in malonic dialdehyde content, along with a 1.4-fold increase in ascorbic acid. Selenium supplementation resulted in an increase in total lipids and mono- and di-unsaturated fatty acids and did not affect the concentration of ω-3 fatty acids and sterol accumulation. Among the identified sterols, only the minor ones (fucosterol, 7-stigmasterol and ∆7-avenosterol) showed a slight decrease upon Se supply. Compared to seeds of cv. Makovey, wild purslane seeds had higher levels of antioxidant activity by a factor of 2 and of polyphenols by a factor of 3.2 but did not differ significantly in oil fatty acid composition. The results indicate the importance of wild purslane leaves/seeds both fortified and not fortified with Se in human nutrition and medicine.

Fruit and vegetable raw materials and processed products contain dietary fibers and biologically active substances, so the use of such raw materials in the manufacture of foods increases their nutritional value. In addition, dietary fibers of fruit and vegetable raw materials can influence the technological properties of food systems. The purpose of this work is determination of the amount of dietary fibers, pectins and the degree of their esterification in fruit and vegetable powders, as well as establishment of an impact of these parameters on the technological properties of confectionery glazes with the addition of fruit and vegetable powders (taking into account the ability of the latter to absorb fat). Objects of research are powders of carrots, apples, beets, raspberries and model samples of confectionery glazes with their addition. Rheological parameters of confectionery glazes were determined by the Casson method on a rotary viscometer. The content of dietary fibers was established by the enzymatic-gravimetric method. Pectins from powders were isolated by acid hydrolysis of raw materials followed by ethanol precipitation. A degree of esterification of pectins was calculated on the basis of the results obtained by potentiometric titration. It has been found that the studied fruit and vegetable powders from domestic raw materials were characterized by a high amount of dietary fibers (24–38%), the main part of which was represented by pectin. Beet and raspberry powders contained low esterified pectins (18 and 33 g/100 g); apple and carrot powders contained highly esterified pectins (16 and 27 g/100 g). Powders with low esterified pectins showed a moderate increase in the Casson yield strength of the glazes with their addition that did not exceed the optimal values of this indicator. With increasing concentrations of powders with highly esterified pectins, a sharp increase in the Casson yield strength of the glazes was observed. At concentrations of 13% and more, this indicator exceeded the optimal values. Thus, in the development of confectionery glazes with fruit and vegetable powders, prediction of their maximum concentration can be carried out by determining the content of dietary fibers, pectins and a degree of their esterification, as well as by taking into account pH and the ability of powders to absorb fat.