2.4.4. Total phenolics
Total phenolics content was determined by spectrophotometry
using Folin–Ciocalteau reagent method (Lu et al., 2007) with slight
modification. A freeze-dried sample was extracted with 70% ethanol
and then reacted with a 10-fold diluted Folin–Ciocalteau reagent.
Sodium carbonate at a concentration of 7.5% (w/v) was
added, and the final volume was made up with deionized water.
508 K. Judprasong et al. / Food Chemistry 140 (2013) 507–512After incubation at room temperature in the dark for 2 h, the mixture’s
absorbance was measured against the gallic acid standard at
760 nm. Total phenolic contents were expressed as mg gallic acid
equivalent (GAE)/100 g sample