Abstract: Functional peptides are widely found in nature. The naturally occurring peptides in the human body are referred to as endogenous peptides, which are closely related to the physiological activities such as growth, metabolism, immunity, and conduction of living organisms. Exogenous peptides, with the various functions such as anti-tumor, blood pressure lowering, bone health peptides, can be gained by proteins degradation and amino acid synthesis. However, endogenous peptides are mostly present in low abundance, and are highly susceptible to high-abundance proteins during enrichment; exogenous peptides are mixed with other components. Therefore, the isolation of exogenous peptides and the enrichment of endogenous peptides to obtain the target peptide are prerequisites for studying their structure and function. In this paper, the separation methods of exogenous peptides and the enrichment methods of endogenous peptides are introduced respectively, focusing on the principles, applicable objects, advantages and disadvantages as well as development directions of various methods. This paper will lay a foundation for the structural analysis and functional development of functional peptides.

Key words: functional peptide, endogenous peptide, exogenous peptide, enrichment, separation