Natural Phenolic Compounds: A Review of Extraction and Analysis

Phenolic compounds are one of the major classes of secondary metabolites found in plants with enormous diversity of chemical structures and biological activities. They are classified into four main classes: phenolic acids, flavonoids, stilbenes, and lignans, and these compounds are unequally distributed in plant species with varied stability. Therefore, it is obviously necessary to select a proper extraction and analysis method to guarantee a high-yield extraction process and accurate analysis results. In recent years, more and more scientists have paid attention to either conventional or innovative methods for recovering phenolic compounds from the sample matrix. In order to give an overview of recent studies about phenolic compounds, this review will mainly focus on extraction and analysis methods and discuss some research directions that will receive more attention in the near future.