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.