Determination of selenium species in beetroot juices

Aleksandra Sentkowska; Krystyna Pyrzynska

doi:10.1016/j.heliyon.2020.e04194

Determination of selenium species in beetroot juices

Heliyon. 2020 Jun 13;6(6):e04194. doi: 10.1016/j.heliyon.2020.e04194. eCollection 2020 Jun.

Authors

Aleksandra Sentkowska¹, Krystyna Pyrzynska²

Affiliations

¹ Heavy Ion Laboratory, University of Warsaw, Pasteura 5A, 02-093 Warsaw, Poland.
² Department of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland.

Abstract

Over the past years, there is an increasing demand for healthy, natural foods. Due to the high content of betalains, beetroots are widely used in the food industry as a natural colorant. In this study, beetroot juices are shown as a great source of selenium compounds. The juices were purchased from a local store and the ecological one was purchased form organic street market. The content of organic selenium species, as well as betalains, were evaluated using hydrophilic interaction liquid chromatography (HILIC) chromatography. The concentrations of selenomethionine (SeMet) and methylselenocysteine (MeSeCys) in analyzed juices were comparable except for juice from ecological cultivation. In that case, the concentration of SeMet is the highest of all studied juices, but simultaneously the concentration of MeSeCys was the lowest one. No traces of major inorganic species of Se, such as Se(IV) and Se(VI) was detected. The reducing power of juices evaluated by Folin-Ciocalteu assay was in range 50.78-166.7 mg GA/L. Juices obtained from beetroot from ecological cultivation showed the highest ability to scavenge the 1,1-diphenyl-2- picrylhydrazyl (DPPH) radicals. There was a correlation between the yellow pigment content and the presence of selenocysteine in studied juices.

Keywords: Antioxidant activity; DPPH; Folin-ciocalteu method; Food analysis; Food science; Methylselenocysteine; Selenomethionine.