Carrot (Daucus carota L. s sp. sativus (Hoffm.) Arcang.) is a significant source of vitamins (A, B, C) and beta carotene. Further it contains vitamins B, C, E, H, folic acid and pantothenic acid. Carrot is an important source of trace elements (K, Na, Ca, Mg, P, S, Mn, Fe, Cu and Zn). Consumption of carrot improves eyesight, lowers cholesterol and improves digestion. In this work we evaluated and compared content of total polyphenols, ß-caroteneand antioxidant activity in five varieties of carrot (’Jitka’, Kardila’, Katlen , Rubína’ and Koloseum) Samples of carrot were collected at full maturity stages from area of Bardejov. Samples of fresh carrot were homogenized (25 g) in 50 ml 80 % ethanol and analysed after sixteen hours. The content of the total polyphenols was determined by using the Folin-Ciocalteu reagent (FCR). The content of ß-carotene was determined spectrophotometricaly at 450 nm. Antioxidant activity was measured using a compound DPPH (2.2-diphenyl-1-picrylhydrazyl) at 515.6 nm using spectrophotometer. Total polyphenols content in samples ranged from 81.25 ± 13.11 mg/kg to 113.69 ± 11.57 mg/kg and content of ß-carotenes ranged from 24.58 ± 2.38 mg/kg to 124.28 ± 3.54 mg/kg. We also evaluated and compared the antioxidant activity in selected varieties of ca rrot, which varied from 6.88 ± 0.92 % to 9.83 ± 0.62 %. Statistically si gnificant the highest value of total polyphenols was recorded in variety of Koloseum (113.69 ± 11.57 mg/kg). This variety is also character ized by the highest content of ß- carotene (124.28 ± 3.54 mg/kg) as well as the highest value of antioxidant activity (9.83 ± 0.62 %).

Red beetroot (Beta vulgaris rubra) is an important raw material of plant origin with proven positive effects on the human body. They can be eaten raw, boiled, steamed and roasted. Red beetrooot is a rich source of minerals substances (manganese, sodium, potassium, magnesium, iron, copper). Beetroot contains a lot of antioxidants, vitamins (A, C, B), fiber and natural dyes. Red beetroot is also rich in phenol compounds, which have antioxidant properties. These colorful root vegetables help protect against heart disease and certain cancers (colon cancer). In this work we evaluated content of total polyphenols and antioxidant activity in red beetroot. Samples of plant material were collected at full maturity stages from areas of Zohor, Sihelné, and Sliač. Zohor, Sihelné, and Sliač are areas without negative influences and emission sources. Samples of fresh red beetroot were homogenized and were prepared as an extract: 50 g cut beetroot extracted by 100 ml 80% ethanol for sixteen hours. These extracts were used for analyses. The content of the total polyphenols was determined by using the Folin-Ciocalteu reagent (FCR). The absorbance was measured at 765 nm of wavelength against blank. Antioxidant activity was measured using a compound DPPH˙ (2.2-diphenyl-1-picrylhydrazyl) at 515.6 nm in the    spectrophotometer. In the present experiment it was detected, that total polyphenols content in samples ranges from 820.10 mg/kg to 1280.56 mg/kg. Statistically significant highest value of total polyphenols was recorded in beetroot in variety of Renova from locality of Sliač (1280.56 ±28.78 mg/kg). Statistically significant the lowest content of total polyphenols was recorded in beetroot in variety of Renova from the village Sihelné (820.10 ±37.57 mg/kg). In this experiment the antioxidant activity in beetroot was evaluated and compared. The values of antioxidant activity were in interval from 19.63% to 29.82%.

The species of the genus Allium are very important crops for human health. They contain many health beneficial substances, such as polyphenols (especially flavonoids), sulphur compounds, vitamins, mineral substances and substances with antioxidant activity. This work has focused on the comparison of total phenolic content and antioxidant activity of selected species of the genus Allium -garlic (Allium sativum L.), chives (Allium schoenoprasum L.), ramson (Allium ursinum L.) and red, yellow and white onion (Allium cepa L.). Samples of plant material were collected at the stage of full maturity in the area of Nitra. Total polyphenols content was determined using the spectrophotometric method of Folin-Ciocalteu agents. Determined the content of total polyphenols were in the range 444.3 -1591 mg*kg -1 . Total polyphenols content in the observed crops declined in the following order: chives > red onion > garlic > yellow onion > ramson > white onion. Antioxidant activity was measured by the spectrophotometric method using a compound DPPH (2.2-diphenyl-1-picryhydrazyl). Determined the value of antioxidant activity ranged 12.29 -76.57%. Antioxidant activity observed in crops declined in the following order: chives > ramson > red onion > yellow onion > garlic > white onion. In all the analysed crop plants was confirmed by the strong dependence of the antioxidant activity and the total content of polyphenolic substances. AbstraktDruhy z rodu Allium sú veľmi dôležité plodiny pre ľudské zdravie. Obsahujú množstvo dôležitých zdraviu prospešných látok, medzi ktoré patria polyfenoly (hlavne flavonoidy), sírne zlúčeniny, vitamíny, minerálne látky a látky s antioxidačnou aktivitou. Táto práca bola zameraná na porovnanie obsahu celkových polyfenolov a antioxidačnej aktivity vo vybraných druhoch z rodu Allium -cesnak (Allium sativum L.), pažítka (Allium schoenoprasum L.), cesnak medvedí (Allium ursinum L.) a červená, žltá a biela cibuľa (Allium cepa L.). Vzorky rastlinného materiálu boli zhromažďované v štádiu plnej zrelosti v lokalite Nitra. Obsah celkových polyfenolov bol stanovený spektrofotometrickou metódou s použitím Folin-Ciocalteuovho činidla. Stanovené obsahy celkových polyfenolov sa pohybovali v rozmedzí 444.3 -1591 mg*kg -1 . Obsah celkových polyfenolov v sledovaných plodinách klesal v nasledujúcom poradí: pažítka > červená cibuľa > cesnak > žltá cibuľa > cesnak medvedí > biela cibuľa. Antioxidačná aktivita bola meraná spektrofotometrickou metódou za použitia zlúčeniny DPPH (2.2-difenyl-1-pikryhydrazyl). Stanovené hodnoty antioxidačnej aktivity sa pohybovali v rozmedzí 12.29 -76.57%. Antioxidačná aktivita v sledovaných plodinách klesala v nasledujúcom poradí: pažítka > cesnak medvedí > červená cibuľa > žltá cibuľa > cesnak > biela cibuľa. Vo všetkých analyzovaných plodinách bola potvrdená silná závislosť medzi antioxidačnou aktivitou a celkovým obsahom polyfenolických látok.

Vegetable are widespread throughout the world and is a major part of the human diet. From the perspective of agricultural crops that belong to the group of Beta vulgaris (beetroot, mangold, sugar beets, fodder beet) are first-rate vegetables. Especially popular is used in the food industry for the production of sugar, various vegetable juices, coloring agents, and many other products. Beetroot (Beta vulgaris L.) is considered one of the ten most important vegetable in the world, thanks to the content of rare natural pigments (betalains), polyphenols, flavonoids, antioxidants, vitamins, minerals and fiber. In this work we evaluated content of bioactive substances, especially the content of total polyphenols, anthocyanins and antioxidant activity in several varieties (Cylindra, Kahira, Chioggia, Crosby Egyptian) of beetroot (Beta vulgaris L.). Samples of plant material were collected at full maturity stages from areas of Zeleneč (Czech Republic). Zeleneč is area without negative influences and emission sources. Samples of fresh beetroot (Beta vulgaris L.) were homogenized and were prepared as an extract: 50 g cut beetroot (Beta vulgaris L.) extracted by 100 mL 80% ethanol for sixteen hours. These extracts were used for analyses. The content of the total polyphenols was determined by using the Folin-Ciocalteu reagent (FCR). The absorbance was measured at 765 nm of wavelength against blank. The content of total anthocyanins was measured at 520 nm wavelength of the blank. Antioxidant activity was measured using a compound DPPH˙ (2.2-diphenyl-1-picrylhydrazyl) at 515.6 nm in the spectrophotometer. In the present experiment it was detected, that total polyphenols content in samples ranges from 218.00 mg.kg -1 to 887.75 mg.kg -1 , total anthocyanins content in samples ranges from 14.48 ±0.40 mg.kg -1 to 84.50 ±4.71 mg.kg -1 and values of antioxidant activity were in interval from 8.37 ±0.29% to 21.83 ±0.35%.

Quince fruit (Cydonia oblonga Miller) is an important source of bioactive compounds, especially of polyphenolic compounds, phenolic acids, flavonoids also of minerals and vitamins. This compounds exhibit health promoting properties including antibacterial, anti-inflammatory, anticancer, antidiabetic and cardioprotective properties. Quine fruit have a high therapeutic value, can be used as good sources of antioxidants. This study provides some knowledge about content of total polyphenols, ascorbic acid and antioxidant activity in selected varieties of quince fruit samples. Four quince fruit cultivars (Semenáč, Konstantinopler Apfelquitte, Cydora Robusta, Mammut) were analysed. The content of the total polyphenols (TPC) was determined by the Folin-Ciocalteu reagent (FCR) at 765 nm using spectrophotometer. Ascorbic acid (AsA) content was determined using standard HPLC gradient method. Antioxidant activity (AA) was measures using a compound DPPH˙(2.2-diphenyl-1-picrylhydrazyl). The content of (TPC) in fresh samples of quince fruit ranged from 661 ±11.60 mg.kg -1 to 1044 ±11.03 mg.kg -1 and content of AsA were in interval from 151 ±0.58 mg.kg -1 to 215 ±0.75 mg.kg -1 . The values of antioxidant activity in quince fruit samples were in range from 26.90 ±0.61% to 49.14 ±0.38%. Statistically significant highest content TPC, AsA and AA was recorded in cultivar Konstaninopler Apfelquitte and statistically lowest content was recorded in cultivar Semenáč. The content of TPC, AsA and AA beside the variety may be affected by many factors also climatic conditions and the agrochemical composition of the soil.