In many cases people use methods that rely on the reducing power of phenolics. these are well determined and abundant methods, e.g. Folin-Ciocalteu reagent. However, it is important to bare in mind that other reducung agents will also react in these mixtures, and one major concern in plant material is ascorbic acid, better known as vitamin C.
To avoid this, you should use chromatographic means to partially purify your plant extract, or better, use HPLC to specifically determine known compounds, or unknown using a known standard to normalize.
You can use the spectrophotometric method of Folin-Ciocalteau:
V.L. Singleton, J.A. Rossi, Colorimetry of total phenolics with phosphomolybdic phosphotungstic acid reagents, Am. J. Enol. Viticult. 16 (1965) 144-158.
If you have to extract the phenolic compounds from a vegetal matrix it is possible follow this:
E. Revilla, J.M. Ryan, G. Martìn Ortega, Comparis on of several procedures used for the extraction of anthocyanins from red grapes, J. Agr. Food Chem. 46 (1998) 4592 – 4597.
The problem is that tannins are not the only phenolic molecules present in plants
- Badges
- Science topic
- Similar topics
- Biological Science
- Plant Sciences
- Ethnobotany