The use of buckwheat as a source of rutin for medicine or food supplement requires a high content of this component in pimary row materials. The study was aimed at the investigation of the influence of stand density and sowing dates on the rutin content in the aboveground parts at the stage of flowering and achenes of two buckwheat species (Fagopyrum esculentum and Fagopyrum tataricum). The rutin content in the aboveground parts of buckwheat was significantly higher in plants sown in mid-May. The sowing date did not influence the rutin content in the achenes. The whole buckwheat plant contained the highest content of rutin in 25 cm rows with a sowing ratio of 200 achenes per square metre. However, the final rutin amount obtained from a buckwheat stand depended on the production of biomass. Common buckwheat provided a higher rutin yield because it produced a higher amount of biomass of inflorescences, the part rich in this flavonoid. Therefore 12.5 cm rows with 400 seeds per square metre are suitable for rutin production because of the higher number of plants. We can recommend tartary buckwheat for achene production as a source of rutin for human nutrition or food supplement because it provides twenty-fivefold more rutin than common buckwheat.
Five varieties of common buckwheat (
Moench) were tested in field experiments for three years. The aim of the study was to investigate the influence of the variety and environmental conditions on rutin distribution in the plant. The rutin content was determined by micellar electrokinetic capillary chromatography in stems, leaves and flowers at flowering stage and in achenes at maturity. The selected varieties differed statistical significantly in the rutin content in leaves, stems and achenes. Krupinka was the variety with the highest rutin content in the aboveground part of a plant. The tetraploid variety did not contained higher rutin level than diploid varieties. Krupinka had the highest rutin content in leaves contrary to the other varieties, which had the highest rutin content in flowers. Weather conditions influenced the rutin content in flowers, stems and achenes. The plant part with the highest rutin content can be different in diverse years.
Authors:E. Dadáková, N. Vrchotová, Š. Chmelová and B. Šerá
Black elder inflorescence has been traditionally used in Central Europe both in folk and official medicine. This plant material is a rich source of two biologically active components, rutin and chlorogenic acid. Nevertheless, there is a lack of data on the changes of their content during processing.The stability of rutin and chlorogenic acid during drying and the long-term storage of black elder inflorescence were analysed in this study. The rutin content was determined by capillary electrophoresis using solid-phase extraction. HPLC was used for the determination of chlorogenic acid. The dependence of rutin and chlorogenic acid content on the temperature of drying and storage duration were monitored and statistically evaluated by a two-way ANOVA test. The contents of rutin and chlorogenic acid revealed no statistically significant changes when dried at temperatures of 22 °C and 30 °C. The significant decrease in contents of both studied compounds was found at a drying temperature of 50 °C. The decrease in content of rutin was about 20%, in chlorogenic acid about 12%.The content of both studied compounds also decreased after long-term storage (at a temperature of 22 °C for one year). The decrease in content of rutin was greater than that of chlorogenic acid.
Authors:J. Bystricka, J. Musilova, J. Tomas, J. Noskovic, E. Dadákova and P. Kavalcova
Onion bulbs (Allium cepa L.) are good sources of flavonoids. The aim of this study was to analyse the changes in dynamics of quercetin formation in three varieties of onions (white, yellow, and red) during the vegetation period. Quercetin content was determined after acid hydrolysis (1.2 M HCl in 50% aqueous methanol) by high-performance liquid chromatography (HPLC). The content of total phenolics was determined using Folin-Ciocalteu reagent (FCR) according to LACHMAN and co-workers (2003). The content of polyphenols in onion ranged from 2893 to 6052 mg kg–1 and the content of quercetin ranged from 52.44 to 280.72 mg kg–1 in fresh matter. The highest content of polyphenols and quercetin was found in the red variety. According to statistical analysis the dynamic of quercetin formation in all cultivars had statistically moderate (P<0.05) increasing tendency. Increasing content of polyphenols was accompanied with slight increase of quercetin, but the differences remained insignificant (P<0.05).