The influence of variety on the content of bioactive compounds in beetroot (Beta vulgaris L.)

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 Zelenec (Czech Republic). Zelenec 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%.