Vollmannová A., Margitanová E., Tóth T., Timoracká M., Urminská D., Bojňanská T., Čičová I. (2013): Cultivar influence on total polyphenol and rutin contents and total antioxidant capacity in buckwheat, amaranth, and quinoa seeds. Czech J. Food Sci., 31: 589-590.Five cultivars from each of the three types of pseudocereals, i.e. buckwheat, amaranth, and quinoa, were studied for total polyphenol and rutin contents as well as total antioxidant capacity of seeds. A spectrophotometric method was used for the determination of total polyphenol content (using the Folin-Ciocalteau reagent) and total antioxidant capacity (using DPPH). Rutin content in pseudocereal seeds was determined by HPLC. The determined total polyphenol content in seeds of buckwheat, amaranth, and quinoa cultivars was in the intervals of 15 874-71 359 mg/kg DM, 1381-2870 mg/kg DM, and 459-1839 mg/kg DM, respectively. Rutin content in buckwheat, amaranth, and quinoa seeds was in the intervals of 8722-17 125 mg/kg DM, 310-508 mg/kg DM, and 170-368 mg/kg DM, respectively. The presented results confirmed a statistically significant influence of cultivar on total polyphenol and rutin contents as well as on total antioxidant capacity of pseudocereal seeds.

The changes of dynamics of total polyphenolics formation in various anatomical parts (stems, leaves, flowers and seeds) of common buckwheat (Fagopyrum esculentum Moench.) during vegetation period were surveyed. Six cultivars were analysed: Pyra, Spacinska, Emka, Kasho, Jana C1 and Hrusowska. The content of total polyphenolics was evaluated in growth phase I. (formation of buds), in phase II. (at the beginning of flowering), in phase III. (full blossoming) and in phase IV. (full ripeness). The total polyphenolics content was assessed by using Folin-Ciocalteau assay spectrophotometrically on Shimadzu UV-1800. When evaluating all four anatomical parts of common buckwheat we can state that the flowers contained the highest concentration of total polyphenolics where the values were in range from 14.93 to 25.16 mg.g -1. In last phase (IV. phase) where stems, leaves, and seeds were evaluated, buckwheat leaves exerted the highest content of these compounds, and the values were in range from 68.74 to 90.27 mg.g -1. Maximal increase of total phenolics content was manifested in each variety in phase IV., i.e. at the end of the vegetation period. From the standpoint of the content of total polyphenolics in individual anatomical parts the cultivars Pyra, Hrusowska and Emka were the most suitable ones as functional foods.

Abstract:The changes of total anthocyanins (TA) content in fruit of blueberries in relation to freezing duration are the aim of this study. The samples of 21 chosen cultivars obtained from the research breed station were stored in polyethylene bags in freezing box at temperature -18°C. In ethanolic blueberry extracts TA contents were by spectrophotometric method during the time of 6 months at period of 3 months determined. Significant differences of TA content among the observed cultivars were confirmed. The value interval was 615.8-3206.3 mg/kg. The average TA content in 10 very early, resp. early cultivars was 1655.8 mg/kg, in 5 medium early cultivars 1515.6 mg/kg, in 6 medium late, resp. late cultivars 1431.2 mg/kg. During 6 months of blueberries store in the freezing box the average decrease 16.7% of TA content was observed. The average decrease of TA content in very early, resp. early cultivars was 19.6%, in medium early cultivars 16.5% and in medium late, resp. late cultivars 14%.

Total content of polyphenols was investigated in different anatomical parts of amaranth during different growth periods. Five amaranth cultivars were included in the experiment (Amaranthus hypochondriacus L.: cultivars Annapurna and Koniz, Amaranthus caudatus L.: cultivar Oscar Blanco, Amaranthus cruentus L.: cultivars Golden Giant and Rawa). Analysis were done in 4 growth phases: phase I. – intensive stem growth, phase II. – formation of the flowers and pollination, phase III. – milky ripeness, phase IV. – full ripeness. Based on the determined total polyphenol content in amaranth it is possible to create this anatomical part order: leaves > flowers > seeds > stems. No statistically significant differences were confirmed between phases I., III. and IV. On the other hand the total polyphenol content in amaranth determined in growth phase II. was significantly different in comparison to other growth phases. Statistically significant differences in polyphenolic content were confirmed between all investigated anatomical parts of amaranth.