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.

The aim of the paper was to evaluate the phenolic acid content and antioxidant properties in potato cultivars with coloured flesh and bright flesh. The study material included eight cultivars of edible potato grown in a temperate climate in Poland. Five cultivars were potato tubers with coloured flesh: “Rote Emma”, “Blue Salad”, “Vitelotte”, “Red Emmalie”, and “Blue Congo”; and three were potato tubers with bright flesh: “Bella Rosa”, “Lord”, and “Tajfun”. In all potato samples under study, four phenolic acids were identified: chlorogenic acid, gallic acid, p-coumaric acid, and caffeic acid. The predominant acid was chlorogenic acid, the levels of which ranged from 62.95 mg·100 g⁻¹ FM to 126.77 mg·100 g⁻¹ FM. The total concentration of the identified phenolic acids was diverse and depended on the genotype of the cultivar and the tuber flesh colour, with coloured-fleshed potatoes having higher phenolic acid contents in comparison to bright-fleshed potato cultivars. The average concentration of phenolic acids in the samples was 89.19 mg∙100 g⁻¹ FM, and the average concentrations of the individual phenolic acids identified were as follows: chlorogenic acid (86.19 mg∙100 g⁻¹ FM), gallic acid (1.18 mg∙100 g⁻¹ FM), p-coumaric acid (0.64 mg∙100 g⁻¹ FM), and caffeic acid (1.18 mg∙100 g⁻¹ FM). In addition, three groups of anthocyanins were identified: pelargonidin-3,5-di-O-glucoside, peonidin-3,5-di-O-glucoside, and petunidin-3,5-di-O-glucoside. Anthocyanins were not found in the “Lord” or “Tajfun” varieties characterised by white tuber flesh. The predominant pigment was petunidin-3,5-di-O-glucoside, with an average content of 23.15 mg∙100 g⁻¹ FM, and the highest value was observed in the “Vitelotte” variety (51.27 mg∙100 g⁻¹ FM). The antioxidant activity of the flesh of the potatoes under study was diverse depending on flesh colour. The FRAP (Ferric Reducing Antioxidant Power) assay indicated higher antioxidant activity of coloured-fleshed potato cultivars. The highest concentration was identified in the “Vitelotte” cultivar flesh and was 114% higher than in the “Lord” cultivar. Similar dependencies were found in the case of the DPPH (2,2-diphenyl-1-picrylhydrazyl) assay; however, in this case, the “Vitelotte” cultivar flesh demonstrated nearly 6.4 times higher antioxidant activity than the “Lord” cultivar. Summarizing our own research, we can conclude that potato varieties with coloured flesh are characterised by a higher content of biologically active substances, including phenolic acids, and antioxidant properties compared to potato tubers with bright flesh.

The research focuses on the effects of temperature on the quality and storage stability of sweet potato (Ipomoea batatas L. [Lam]). It is based on the results of a field experiment conducted between 2015–2017 in Żyznów (49°49′ N, 21°50′ E). The experimental factors were: storage temperatures (5° and 15 °C) and sweet potato cultivars (‘Carmen Rubin’, ‘White Triumph’, ‘Beauregard’, ‘Satsumo Imo’, ‘Purple’). Tubers were harvested at BBCH stage 97. Tubers were stored in a climatic chamber with temperature control and fixed ambient humidity for 6 months during the 2015/16–2017/18 seasons. The storage of tubers at 15 °C helped reduce tuber waste and weight losses resulting from germination, transpiration, respiration and rotting. The quality of the stored tubers depended mostly on storage temperature. It was observed that at 15°, the content of dry matter and total sugars was higher than at 5°, whereas the content of starch was lower. The factor determining storage stability was the genetic features of the cultivars under study. The cultivars ‘Purple’ and ‘Satsumo Imo’ demonstrated good storage stability. The cultivar ‘Carmen Rubin’ turned out least suitable for long storage. The experiment results can contribute to developing storage technology of sweet potato tubers cultivated in Central Europe.

Both nitrogen and sulphur are important macronutrients necessary for the proper development and yield of soybean. Moreover, sulphur plays a special role in nitrogen metabolism in the plant, and sulphur deficiency leads to a reduction in the utilization of nitrogen from fertilizer. The objective of this study was to assess the effect of nitrogen and sulphur application on the yield and quality traits of soybean seeds. The following factors were analyzed in the experiment: I. Nitrogen application rate: 0, 30 and 60 kg ha⁻¹ applied at different times (before sowing and/or at the start of the seed filling stage); II. Sulphur application rate: 0 and 40 kg ha⁻¹ applied in two portions: half during the development of lateral shoots and half at the start of flowering. Thus the 14 fertilizer combinations were obtained. Result show that the highest seeds yield was obtained in the combinations with 60 kg N applied ½ before sowing + ½ after emergence (BBCH 73-75) and ¾ before sowing +¼ after emergence. In these combinations, sulphur did not significantly affect seed yield. In the remaining nitrogen application, sulphur application significantly increased the seed yield. Taking into account the yield and the chemical composition of the soybean seeds, fertilization with 60 kg N ha⁻¹ in two portions can be recommended—½ or ¾ before sowing and the remainder during the development of pods and seeds—in combination with sulphur application.

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.