Abstract:

Three analytical methods (ferrous tartrate colorimetry, Folin-phenol reagent method and UV spectrophotometry)
were compared for the determination of total phenolics in Chinese olive in this study. The results showed the three
methods followed the decreasing order: UV spectrophotometry ＜ Folin-phenol reagent method ＜ ferrous tartrate
colorimetry by detection limit and quantitation limit with a significant difference among them (P ＜ 0.05), and ferrous
tartrate colorimetry ＞ Folin-phenol reagent method ＞ UV spectrophotometry by recovery with the difference being not
significant. All these three methods had good repeatability. The polyphenol content determined by Folin-phenol reagent
method and UV spectrophotometry was significantly higher than that determined by ferrous tartrate colorimetry (P ＜ 0.01),
and the polyphenol content determined by Folin-phenol reagent method was slightly higher than that determined
by UV spectrophotometry, with the difference being not significant (P ＞ 0.05). At the same time, there was a good
linear relationship of total polyphenol contents determined by two of them. In comparison two other methods, UV
spectrophotometry proved more suitable for the determination of total phenolics in Chinese olive, thanks to its high
sensitivity, good repeatability, simplicity, rapidity, accuracy and economy.

Key words: Chinese olive, phenolics, ferrous tartrate colorimetry, Folin-phenol reagent method, UV spectrophotometry