As ascorbic acid also reacts with the FolineCiocalteu reagent,
total phenolic contents were corrected for the ascorbic acid interference,
according to Asami, Hong, Barrett, and Mitchell (2003).
The same methodology used for total phenolics quantification was
performed for ascorbic acid standards and a calibration curve was
obtained.
The concentrations of ascorbic acid measured spectrophotometrically
as described in Section 2.4.1 were then used to
evaluate the contribution of the ascorbic acid to the absorbance
detected in the total phenolics assay and subtracted from it.
Total phenolics were then quantified by means of a calibration curve
obtained from measuring the absorbance of gallic acid standards
and expressed in mg per 100 g of fresh weight.