Biologically active phenolic compounds in buckwheat, oats and winter spelt wheat

Abstract

The current study was aimed to determine the total phenolic content and antioxidant activity, rutin, quercetin and phenolic acids content in buckwheat, husked and common oats, winter spelt, winter and spring wheat grain with and without husks or glume, only husks or glume as well as to estimate phenolic compounds ratio and to compare their distribution between cereal grain and husks or glume. In this way to ascertain the losses of phenolic compounds in grain which will be used for food production. Total phenolic content and antioxidant activity were determined using the spectrophotometric method and individual phenolic compounds were estimated by high performance liquid chromatography. The significantly highest total phenolic content (10.2 ± 1.6 mg g -1 dry weight (d.w.) in grain with husks and 14.1 ± 2.0 mg g -1 d.w. in husks), antioxidant activity (2-4 times), rutin concentration (from 146.5 to 406.3 µg g -1 d.w.) and with a few exceptions hydroxybenzoic acids concentrations of all group of cereal samples (grain with and without husks or glume and only husks or glume) were established for buckwheat. Oats grain without husks or only husks were distinguished by the highest quercetin content, which was higher in husked oats samples (31-89 µg g -1 d.w.). The highest total phenolic acids content was in common oats husks (882.4 µg g -1 d.w.). Ferulic and p-coumaric acid significantly (P < 0.01) predominated in all oats and wheat samples and accounted for about 70-90% of the total phenolic acids content. Syringic acid is characteristic of oats, winter spelt and winter wheat grain without glume and only glume. In all group of cereal samples sinapic acid predominated only in cereal grain with and without husks or glume. Significantly (P < 0.05) higher concentrations of vanillic, p-hydroxybenzoic, 3,4-dihydroxybenzoic, p-coumaric, ferulic acids, total phenolic content, antioxidant activity were quantified in cereal husks or glume compared with those in grain with and without husks or glume.

Phenolics Content in Buckwheat Flour

“…Literature reports that antioxidant activity correlates significantly with the total phenolic concentration (Kerienë et al, 2015). Similar tendencies were observed in this study, where Raw-BF had the highest total phenolic concentration and the highest DPPHÿ radical scavenging activity (27.17 mM TE·100 g -1 DM) among the flour samples.…”

“…This confirms the results of Li et al (2013). Literature indicates that there is a positive correlation between the rutin and total phenolic concentration of buckwheat grain with husks (Kerienë et al, 2015). The current study did not confirm this, as Dark-BF had the highest rutin concentration, whereas Raw-BF had the highest total phenolic concentration among the buckwheat flour samples.…”

“…Rutin concentration, which plays a significant role in the antioxidant capacity of buckwheat seeds (Jiang et al, 2007), was several times higher in Dark-BF (4.613 mg·100 g -1 ) in comparison with other flour. This might be explained by the presence of husks in Dark-BF, as buckwheat husks have been noted to have the highest total phenolic concentration and antioxidant activity (Kerienë et al, 2015).…”

Effect of genotype and crop management systems on the content of antioxidants in hulless and covered spring barley

“…However, the content of major phenolic acids was higher in covered genotypes. Our results partially agreed with a finding that cereal hulls contain significantly higher total polyphenol and most phenolic acid content if compared to cereal grain (Kerienė et al, 2015). Gamel and Abdel-Aal (2012) show the highest concentration of phenolic acids (especially ferulic, p-coumaric and syringic acids) in covered barley hulls followed by outer layers of grain (pericarp and testa) and decreasing towards endosperm.…”

The effect of antifungal extracts on the contamination of grain with microfungi

“…Different solvents used for the Total phenolic content in antifungal extracts preparation of bee product extracts did not have significant effect, therefore, inTable 1we presented average TPCs determined in ethanol and DMSO solvents.Our results agree with those ofSpulber, Colța, et al (2017);Spulber, Doğaroğlu, et al (2017), who suggest that propolis and bee pollen are considered the main bee products with the highest amounts of phenolic compounds and different solvent applied for bioactive substances extraction from bee products do not present significant differences. Our previous studies have shown that buckwheat grain and hulls have the highest amount of total phenolic compounds with the highest antioxidant activity, compared with other cereal grain (Kerienė et al, 2015). The content of individual phenolic compounds in the total phenolics in buckwheat grain and other parts of grain and plant depends on the soil type, cultivation region, and…”