Total Phenol

A previous technique [26,45] was used to determine the total phenol content. One g of dried pepper shoots were extracted in 5–10 mL of 80% ethanol for at least 24 h. After dehydrating the alcohol, the remaining residue was extracted thrice using 5–10 mL of 80% ethanol each time. The purified extract was then filled to a capacity of 50 mL with 80% ethanol, and then 0.5 mL of the extract was mixed well with 0.5 mL of Folin's reagent and shaken for 3 min. After that, 3 mL of purified water and 1 mL of saturated sodium carbonate solution were added and thoroughly mixed. The blue color was detected at 725 nm after 1 h.
