2.7. Measurement of total phenolic content (TPC)
The TPC of crude extracts was evaluated by using modifications
of the Folin–Ciocalteu method (Singleton & Rossi, 1965). Briefly,
200 lL of the appropriate dilutions of crude extracts was reacted
with 1.8 mL of 10-fold diluted Folin–Ciocalteu reagent, which
was freshly made. The mixture was then neutralised with 1.8 mL
of sodium carbonate (60 g/L). The absorbance was measured at
725 nm after 90 min of reaction at room temperature. Ferulic acid
was used as the standard. Results were expressed as mg of ferulic
acid equivalents (FAE) per gram of rice (dry weight basis).