Determination of seed total phenolic content and antioxidant capacity
Prior to the extraction, seeds from plants (n=4) of each treatment were oven-dried at 60ºC for at least 48 hours and then ground. The extraction procedure was adapted from Szydłowska‐Czerniak, Amarowicz & Szłyk (2010). Seeds were extracted with methanol:H2O (50:50, v/v) at a ratio of 20:1 (mg/mL) by using mechanical stirring for 1 h at 25 ºC. Total phenolic content was spectrophotometrically determined with a modified Folin-Ciocalteu method (González-Centeno, Comas-Serra, Femenia, Rosselló & Simal 2015) and was expressed as the mean of six determinations in mg of sinapic acid equivalents per DM g of seeds. Evaluation of the antioxidant capacity (ABTS assay value expressed as mg of trolox equivalents per g of seed DM) was carried out according to the methodology previously described by González-Centeno et al.(2012). Seed extracts were diluted at a ratio 1/4 with methanol:H2O (50:50, v/v) and values were expressed as mg of trolox equivalents per g of seeds DM.