Abstract: Linseed cyclic peptides are important active ingredients in flaxseed, exhibiting antioxidant, anti-inflammatory and anti-cancer properties. However, linseed cyclic peptides undergo partial oxidation during processing and storage, leading to structural changes in [1-8-NαC],[1-MetO2]-linusorb B1. As a result, the bitter compound [1-8-NαC],[1-MetO]-linusorb B1 is produced, which reduces the flavor of linseed-related products, thus limiting the use of linseed in the food industry. This article summarizes the structures and encoding genes of linseed cyclic peptides as well as the methods for their detection. Based on related research, the biological activities of cyclic peptides, the mechanism underlying their bitter taste and the de-bittering methods for them are described. Furthermore, this review envisages the application of linseed cyclic peptides in the pharmaceutical and food fields, and proposes that germination may be a new idea for de-bittering linseed cyclic peptides, with a view to providing a theoretical basis for the integrated regulation of the physicochemical properties and biological activities of linseed cyclic peptides.

Key words: linseed cyclic peptides; structure and function; analytical methods; mechanism underlying bitterness; cyclic peptide oxidation; bitterness removal methods