Effects of solvent types on total phenolic contents and antioxidant capacity of raw cocoa powder
Four solvent types were used to investigate total phenolic contents (TPC) and antioxidant capacity (AC) in raw cocoa powder. The extraction of cocoa powder was conducted at 37°C in acidified solvents (pH 2) including acetone 70% (v/v), methanol 70% (v/v), ethanol 70% (v/v) and distilled water. TPC and AC were measured using Folin-Ciocalteu assay and Trolox equivalent antioxidant capacity (TEAC) assay, respectively. Results showed that the acetone extracts contained the highest TPC (5.2 ± 0.5 gallic equivalent (GAE) 100 g-1, dry matter (DM)) and AC (35.6 ± 2.6 mol Trolox equivalent (TE) 100 g-1 DM). Extracts using ethanol, a green solvent, presented no significant differences in AC and TPC in comparison with those using methanol. Further extractions with various concentrations of ethanol (10, 20, 30, 40, 50, 60 and 70%) showed the variations in TPC and AC in which the ethanol 50% extracts gave the highest AC (38.8 ± 1.5 mol TE 100 g-1 DM).
Yen, D.T.K., Nguyen, Ha V.H. and Nguyen, Hoa D.H. (2018). Effects of solvent types on total phenolic contents and antioxidant capacity of raw cocoa powder. Acta Hortic. 1213, 393-398
raw cocoa powder, antioxidant capacity, total phenolic content, extracting solvent, ethanol, Folin-Ciocalteu assay, acetone, methanol