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%.

Garlic (Allium sativum L.) is one of the most valuable plants in the world because it contains important substances with protective and healing effects on human health. Its health-promoting effects have been already known in ancient Egypt, China, Greece and also the Romans used it. Many studies have shown that garlic can help from colds, coughs, flu, pulmonary diseases, clean blood vessels, lowers blood pressure and cholesterol and has antibacterial, antiviral, anti-carcinogenic, antimutagenic and antioxidant properties. Garlic contains antioxidant that support the body´s defence mechanism against oxidative damage. The physiological effect of garlic can be affected by sulphur-containing compounds as well as other biologically active compounds such as polyphenols (mainly flavonoids), minerals (Ca, Fe, I, K, Mg, Na, Zn) and vitamins (A, B1, B2, B6, C). The main sulphur compound in garlic is alliin, converted to allicin by the enzyme alliinase, which results in a characteristic garlic aroma and taste.

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.

Note: A-B values with different letters mean significant differences (p <0.05) among selected parts of leek; a-h values with different letters mean significant differences (p <0.05) among selected parts and cultivars of leek, values of antioxidant activity are expressed as arithmetic mean

Wild garlic (Allium ursinum L.) is a wildly growing plant that grows in forests and next to the streams. It has a specifi c aroma and taste resembling garlic. Wild garlic is increasingly favoured in gastronomy, food industry, and modern food technologies. The aim of this study was to analyse the dynamics of changes in total polyphenols content (TPC) and antioxidant activity (AOA) in wild garlic leaves and fl owers during the vegetation period (from April to June). The samples of plant material were collected from the area of Bratislava-Železná studienka. The samples of fresh leaves and fl owers were homogenized and a methanolic extract was prepared. These extracts were used for analyses. Total polyphenol content in the samples ranged from 726±10 mg GAE/kg FW to 14.1×10 2 ±13 mg GAE/kg FW. The values of antioxidant activity were from 10.7±1.57 to 25.9±1.06% inhibition FW.

Garlic (Allium sativum L.) is highly regarded throughout the world for both its medicinal and culinary properties. With its bioactive compounds and sulphur containing compounds, high trace mineral content, garlic has shown anti-viral, antibacterial, anti-fungal and antioxidant abilities. This work has focused on the measurement and comparison of the total polyphenols content, the total sulphur content and antioxidant activity of the studied varieties of garlic in the area of Nitra and Bardejov, Slovak Republic. The highest content of monitored indicators (TPC, TSC, AOA) was measured in the area of Nitra. TPC was determined using the spectrophotometric method of Folin-Ciocalteu agents. The total polyphenols content were determined in the range 621.13 to 763.28 mg kg -1 in area of Nitra. The content of total sulphur compounds in the area of Nitra ranges from 0.562 to 0.800 % and in the second area ranges from 0.421 % to 0.658 %. Antioxidant activity was measured by the spectrophotometric method using a compound DPPH. The value of antioxidant activity ranged from 12.01 % to 20.22 % in both monitored locations. The content of TPC, TSC and AOA beside the variety may be affected by the localitylinked factors like climatic conditions and the agrochemical composition of the soil.

Allium is a genus of some 650 species belonging to the family Liliaceae. However only a few of these are important as food plants, notably garlic (Allium sativum L.), onion (Allium cepa L.), leek (Allium porrum L.) and wild garlic (Allium ursinum L.). They contain many health beneficial substances, such as sulphur compounds, vitamins (vitamin C), mineral substances (Fe, Mg, Ca, P), polyphenols (especielly quercetin) and substances antioxidant activity and fiber. In this work we evaluated the content of bioactive substances, especially the content of total polyphenols and antioxidant activity in several species (red onion, yellow onion, white onion, garlic, leek, wild garlic) of the genus Allium. Samples of plant material were collected at full maturity stages from Zohor (Slovak Republic). Zohor is an area without negative influences and emission sources. Samples of fresh species of the genus Allium were homogenized and prepared as an extract: 25 g cut plants material (red onion, yellow onion, white onion, garlic, leek, wild garlic) extracted with 50 mL of 80% ethanol for sixteen hours. These extracts were used for analyzes. The content of total polyphenols was determined using the Folin-Ciocalteu reagent (FCR). The absorbance was measured at 765 nm of wavelength versus blank. Antioxidant activity was measured using DPPH˙ (2,2-difenyl-1-picrylhydrazyl) at 515.6 nm in the spectrophotometer. In the present experiment it was found that total polyphenols content in samples ranged from 83.59 mg.kg -1 to 758.63 mg.kg -1 and values of antioxidant activity were in the range from 7.19% to 53.55%.