Fireweed has recently been recognized as a plant with high antioxidant potential and phenolic content. Its leaves can be fermented to prepare an infusion with ideal antioxidant activity. The aim of this study was to investigate and to determine the influence of solid-phase fermentation of different durations on the variation of polyphenols in the leaves of fireweed. Laboratory experiments were conducted in 2017–2018. The leaves of fireweed, naturally growing, were fermented for different periods of time: not fermented (control) and fermented for 24 and 48 h. The evaluation of polyphenols and antioxidant activity in leaves was performed using high- performance liquid chromatography (HPLC). Additionally, principal component analysis was used to characterize differences in bioactive compounds between fireweed samples fermented at different durations. Solid-phase fermented leaves were characterized by higher contents of oenothein B, quercetin and benzoic acid but had lower contents of quercetin-3-O-rutinoside, luteolin and chlorogenic and gallic acids. Antioxidant activity in short- (24 h) and long-term (48 h) fermentation (compared to control) gave the highest level of regression in 2017, but in 2018 the effect was observed only with short-term fermentation and control. In conclusion, solid-phase fermentation can be used to modulate biologically active compounds in fireweed leaves.

Carotenoids, polyphenols, and ascorbic acid are valuable and important biologically active compounds that contribute to the health benefits of different foods, and rosehips are known for their high biologically active substance contents. The aim of this research is to identify and compare the contents of carotenoids, polyphenols, and ascorbic acid in the flesh and seeds of different rosehip species grown organically. A field experiment was conducted during the period 2017–2018 on an organic farm in Lithuania. Rose fruits were collected at full ripening in September. The quantitative and qualitative determinations of polyphenols and carotenoids in rosehips flesh and seeds were conducted by HPLC methods. The following polyphenolic compounds were identified: five different flavonoids (rutin, kaempferol-3-O-glucoside, luteolin, quercetin, and quercetin-3-O-glucoside) and five phenolic acids (gallic, chlorogenic, caffeic, p-coumaric, and ferulic) from different rose fruit fleshes and seeds species. In addition, six carotenoids (β-carotene, α-carotene, lutein, zeaxanthin, cis-lycopene, and trans-lycopene) in rosehip flesh and five different carotenoids in rosehip seeds (α-carotene, lutein, zeaxanthin, cis-lycopene, and trans-lycopene) were identified. Overall, the results of this study demonstrate that the highest content of total phenolic acid is in rosehip seeds, while higher concentrations of carotenoids, flavonoids, and ascorbic acid are present in rosehip flesh.

The purpose of this research is to evaluate the effect of conventional, biodynamic, and organic cultivation methods on the contents of polyphenols and carotenoids in tubers of potato cultivars with different colored flesh: “Red Emmalie”, “Salad Blue”, “Violetta”, “Tornado”, and “Laura”. These bioactive compounds were determined by the high-performance liquid chromatography method. The data received were analyzed with ANOVA and further explored and visualized by principal component analysis. Higher contents of polyphenols (sum), phenolic acids (sum), chlorogenic acid, p-coumaric acid, and caffeic acid were found in biodynamic and organic samples compared to the conventional tubers. Moreover, organically and biodynamically produced potatoes (except “Salad Blue” cultivar) were significantly richer in flavonoids and anthocyanins. The highest contents of carotenoids (sum), lutein, and β-carotene were found in biodynamic potatoes. Among the tested cultivars, “Tornado”, with white flesh, was richest in polyphenols (sum), phenolic acids (sum), chlorogenic acid, and p-coumaric acid. “Violetta”, with dark purple flesh, accumulated the highest contents of flavonoids (sum), anthocyanins (sum), petunidin-3,5-di-O-glucoside, pelargonidin-3,5-di-O-glucoside, and peonidin-3,5-di-O-glucoside. Carotenoids were only found in “Laura” tubers, and the dominating carotenoid was lutein.

Studies on the determination of the optimal harvest time of rosehips are very limited. Therefore, the aim of this research was to ascertain the effect of the ripening stage on the quality and content of fatty acids of organic rosehip seeds. A two-factor field experiment with two rosehip species and cultivars (Rosa rugosa, Rosa canina, and Rosa rugosa cv. ‘Rubra’, Rosa rugosa cv. ‘Alba’) was conducted during two growing seasons (2018–2019) on an organic farm. The fruits were harvested five times per season. The fatty acid composition of rosehip seeds was determined using a Gas Chromatograph with Split/Splitless Injector Liners. The highest amounts of fat were recorded in all rosehip seeds at ripening stage IV. The most dominant fatty acids in the seed samples were polyunsaturated fatty acids (PUFAs) (73.88–79.52%), followed by monounsaturated fatty acids (MUFAs) (14.67–18.89%) and saturated fatty acids (SUFAs) (5.22–7.36%). The highest amount of PUFAs was established in Rosa rugosa cv. ‘Alba’ seeds harvested at fully ripe stage V. It can be concluded that the rosehip seeds may be utilized as a source of fatty acids, especially PUFAs.

Pumpkin seeds oil are rich in biologically active substances such as a source of tocopherols, carotenoids, especially β-carotene, lutein and other compounds. Also four fatty acids -palmitic, stearic, oleic and linoleic, dominated in the oil of pumpkin seeds oil. The study mainly aimed to evaluate the fatty acid contents and antioxidant parameters of seed oils isolated from different pumpkin cultivars. Investigations of seeds oil from Cucurbita pepo L. 'Miranda', 'Golosemianaja', and 'Herakles' pumpkin cultivars grown in Lithuania revealed that crude fat contents ranged from 44.4% to 47.3%, although 'Miranda' cultivar seeds consistently and significantly had the lowest content. The seed oils contained appreciable amounts of unsaturated fatty acids (approximately 83%), of which polyunsaturated fatty acids, particularly palmitic, stearic, oleic and linoleic acids, were dominant with values ranging from 64.29% to 66.71% of the total amount of fatty acids. The seeds oil were a particularly rich source of linoleic acid (66%), among which 'Miranda' cultivar seeds had the significantly highest content. Our investigation identified that pumpkin seeds oil as a good source of phenolic compounds, particularly cvs. 'Golosemianaja' and 'Miranda' oil. Methanolic seed oil extracts were characterized by statistically significant differences in their antioxidant activity, with the highest antioxidant activity found in cultivar 'Miranda', followed by 'Golosemianaja'. The antioxidant activity level increased proportionally with the total phenolic content, thus establishing a linear relationship between DPPHradical scavenging activity and total phenolic content.

It is believed that fiber-rich diet reduces the risk of certain cancers, coronary heart and other diseases. Dietary fiber (DF) is not only used for its nutritional properties, but also for its functional and technological properties. Thus, to supplement daily diet, dietary fiber should be incorporated into frequently consumed foods. Pumpkins are a good source of carotenoids, mineral salts, vitamins, and other bioactive substances, such as phenol compounds. Also the pumpkin flour could be used for food enriching as fiber supplement. In the study standard methods were applied to determine and compare the neutral dietary fiber (NDF), acid dietary fiber (ADF), acid detergent lignin (ADL) and water-soluble carbohydrates (WSC) contents in pumpkins fruits flour obtained from different species and cultivars. The results imply that pumpkin fruit flour should be recommended as the component suitable for food production with high content of DF. The fiber content in the pumpkin fruit flour depends on the cultivar. The maximum insoluble fiber content (NDF, ADF, ADL) was accumulated in C. maxima 'Kroshka' pumpkin flour: 26.50%, 24.65% and 14.35%, respectively, and this cultivar is the most suitable one for enriching food with dietary fiber.

At present, the consumption of medical plants and functional foods is growing in the whole world. Rosebay willowherb (Chamerionangustifolium (L.) Holub) is an important medicinal plant that has various pharmacological effects (antioxidant, anti-inflammatory, anticancer, and others), can improve the state of health and well-being, and reduce the risk of various diseases. The aim of this work was to investigate volatile compounds, polyphenols, and antioxidant activity in rosebay willowherb leaves fermented for 24 and 48 h in solid state fermentation under aerobic and anaerobic conditions. High-performance liquid chromatography (HPLC) for polyphenols and the spectrophotometric method for antioxidant activity determinations were used. To recognize and identify the leaves’ fragrances, electronic nose (Alpha M.O.S) measurement technology was used. The results showed that the highest amounts of total polyphenols in dried matter were after 48 h aerobic solid state fermentation (SSF). Antioxidant activity was higher under 48 h SSF compared to the control. The most abundant flavoring compound groups were esters, terpenes, and aldehydes. In unfermented leaves, (z)-3-hexen-1-ol, acetate, hexyl acetate, and trans-hex-2-enyl acetate prevailed, characterized by fragrances of greenery, flowers, and fruits. The undesired esters group compounds, ethyl butyrate and butyl acetate, with pungent odor, were detected after 48 h anaerobic SSF.

The article concerns the possibility of the use of geosynthetic materials in hydraulic engineering, with particular emphasis of geotextiles. The geotubes technology and their ability of practical application were shown. The paper also discusses the program of geotechnical field and laboratory tests which was carried out on the experimental plot located on the bank of the Vistula River in Warsaw. Important technical issues deriving from the installation and filling process of geotube were briefly discussed based on observations and experience. In relation to technology of geotubes, attempt of preliminary interpretation of obtained results was made.