Antioxidant activity of a red lentil extract and its fractions.
Phenolic compounds were extracted from red lentil seeds using 80% (v/v) aqueous acetone. The crude extract was applied to a Sephadex LH-20 column. Fraction 1, consisting of sugars and low-molecular-weight phenolics, was eluted from the column by ethanol. Fraction 2, consisting of tannins, was obtained using acetone-water (1:1; v/v) as the mobile phase. Phenolic compounds present in the crude extract and its fractions demonstrated antioxidant and antiradical activities as revealed from studies using a beta-carotene-linoleate model system, the total antioxidant activity (TAA) method, the DPPH radical-scavenging activity assay, and a reducing power evaluation. Results of these assays showed the highest values when tannins (fraction 2) were tested. For instance, the TAA of the tannin fraction was 5.85 micromol Trolox eq./mg, whereas the crude extract and fraction 1 showed 0.68 and 0.33 micromol Trolox eq./mg, respectively. The content of total phenolics in fraction 2 was the highest (290 mg/g); the tannin content, determined using the vanillin method and expressed as absorbance units at 500 nm per 1 g, was 129. There were 24 compounds identified in the crude extract using an HPLC-ESI-MS method: quercetin diglycoside, catechin, digallate procyanidin, and p-hydroxybenzoic were the dominant phenolics in the extract.
Amarowicz
Ryszard
R
Division of Food Science, Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences, Tuwima Street 10, 10-474 Olsztyn, Poland.
Estrella
Isabell
I
Instituto de Fermentationes Industriales (CSIC), Juan de la Cierva 3, 2800 Madrid, Spain.
Hernández
Teresa
T
Instituto de Fermentationes Industriales (CSIC), Juan de la Cierva 3, 2800 Madrid, Spain.
Dueñas
Montserrat
M
Grupo de Investigación en Polifenoles, Unidad de Nutrición y Bromatología, Facultad de Farmacia, Universidad de Salamanca, 37007-Salamanca, Spain.
Troszyńska
Agnieszka
A
Division of Food Science, Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences, Tuwima Street 10, 10-474 Olsztyn, Poland.
Kosińska
Agnieszka
A
Division of Food Science, Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences, Tuwima Street 10, 10-474 Olsztyn, Poland.
Pegg
Ronald B
RB
Department of Food Science and Technology, The University of Georgia, 100 Cedar Street, Athens, GA 30602-7610, USA.
D001547:Benzaldehydes / Q000737:chemistry; D005591:Chemical Fractionation; D016166:Free Radical Scavengers / Q000737:chemistry*; D027806:Lens Plant / Q000737:chemistry*; D010636:Phenols / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry*; D013634:Tannins / Q000737:chemistry; D019207:beta Carotene / Q000737:chemistry
D001547:Benzaldehydes; D016166:Free Radical Scavengers; D010636:Phenols; D010936:Plant Extracts; D013634:Tannins; D019207:beta Carotene; C100058:vanillin