What Can Be Done to Get More—Extraction of Phenolic Compounds from Plant Materials

Polyphenols are a large group of compounds of natural origin, known for their health-promoting effects on the human body. In plant materials, they can be present in the form of glycosides or aglycones, to a different extent bounded to the sample matrix. Their distribution in different parts of the plant may also vary. The extraction process is one of the most important and difficult stages of sample preparation for the analysis of polyphenol compounds. The main goal is to choose the right extraction method to isolate polyphenols from plant samples with the highest possible efficiency and in unchanged forms. This review summarizes some aspects of different extraction methods for phenolic compounds proposed in the last 5 years. Efforts were made to look critically at each of the described extraction methodologies.