The content of polyphenolic compounds in buckwheat grass depending on agrotechnical and abiotic factors and the assessment of the possibility of its use in food technologies

Abstract

Relevance. Buckwheat is a source of many biologically active substances. Especially there are a lot of them in leaves and inflorescences from which it is possible to get tea beverages for specialized and functional nutrition. These plant parts are rich in polyphenolic compounds (PC), the main one being rutin. Their content in the plant depends on many factors.The aim of this study is to estimate the effect of sowing dates, ultraviolet (UV) radiation and temperature on PC accumulation in buckwheat plants.Methods. Buckwheat seeds were sown four times in June-July. The PC content of buckwheat water-ethanol extracts and water infusions was determined by Folin-Ciocalteu, method antioxidant activity — by DPPH radical scavenging method.Results. The sowing dates influence the PC content. At the earlier sowing dates of seeds the accumulation of PC in the extracts was higher (8.42–9.33%) in comparison with the later ones (6.10%). The PC content in the infusions varied from 2.10 to 2.83%. There are indications of a direct relationship between the accumulation of PC and the level of UV radiation during the growing season requiring further verification. A significant effect of temperature was not revealed. The AOA of all samples was high. The content of PC in aqueous infusions allows us to recommend buckwheat grass as a raw material for tea beverages.