Abstract: Phenolic compounds have function to prevent chronic diseases related to oxidative stress. Plants are the main source of phenolic compounds for humans, and in-depth exploration of phenolic compounds is of great significance for the development of functional foods. In recent years, increasing studies have demonstrated that phenolic compounds are present in plant matrices in free and bound forms, which affect their in vivo metabolic pathways and biological activities. In this review, the methods used for the separation and extraction of free and bound phenolic compounds, their distribution in plant tissues and organs and in vitro and in vivo activities, and the factors affecting their distribution are summarized, which will provide valuable information for scientific development of functional foods rich in phenolic compounds.

Key words: phenolic compounds, existing form, free phenolics, bound phenolics, functional foods