Fasan Israel Just extract with 80% acetone in water to get phenolic rich fraction. You don't have to remove fat. See the method section in below paper. Thanks.
Conference Paper Purification of model tannins from 13 branches of the hydrol...
Fasan Israel Every plant contains some level of phenolics, some plants might contain more or less. However, if you want to work with phenolics then you have to cold extract certain way like using 80% acetone in water to accumulate phenolics in solvent. Then when you dry that you get mainly phenolics which could be phenol rich fraction you want. Acetone is easy to evaporate even at room temp. and then you can freeze dry aqueous sample.
Fasan Israel In standard practice, we evaporate acetone in concentrator using vacuum pump under nitrogen flow and then we do freeze drying. However, you might not have all those instruments. In that case you can use rotary evaporator but make sure the temperature stays between 40-60 Celsius, lower is better as phenolics are degraded by high temperature.