2.6. Total polyphenol content
Total polyphenol content in ginger oleoresin prepared from ginger
with enzyme treatment and in control sample was estimated
by the Folin–Ciocalteu method (Yen & Duh, 1994). The Folin–Ciocalteau
reagent (FCR) reacts with polyphenol compounds in the
alkaline medium and forms complexes with maximum absorbance
at 750 nm. One ml of 1:10 diluted Folin–Ciocalteu reagent was
added to 0.2 ml of 1:10 diluted oleoresin samples; after 4 min,
0.8 ml of aqueous sodium carbonate (75 mg/ml) was added. After