Total proteins concentration in water-soluble sunflower seed
extracts was determined with the Bradford colorimetric method
(Bradford, 1976). Briefly, to a 1 mL aliquot of a protein solution
1 mL of prepared Bradford reagent (100 mg of Coomassie Blue
was mixed in a 1000 mL glass flask with 50 mL of 95% ethanol
and 100 mL 85% (v/v) phosphoric acid and diluted with deionised
water) was mixed in a test tube and vortexed for 30 s before the
absorbance of the solution was measured at 595 nm on a UV–Vis
spectrophotometer (Varian, USA). A reference solution was prepared
in identical manner as explained above, except that the
1 mL aliquot of protein solution was replaced by deionised water.
The quantification was done based on a calibration curve obtained
with BSA (Albumin Bovine Serum). Total proteins content in water
soluble extracts (wBSA) was expressed in mg of BSA per g of extract
(mg BSA/g ext.).