Abstract: Hazelnut protein isolate hydrolysate was ultrafiltrated to obtain peptides with molecular weight less than 3 kDa. Further purification and structural identification were carried out using gel filtration chromatography and reversedphase high-performance liquid chromatography (RP-HPLC). The results showed that fraction B1, separated on a column of Sephadex G-15, could significantly decrease the production of TNF-α and IL-6 (P < 0.01) in RAW264.7 cells. The peptide Pro-Glu-Asp-Glu-Phe-Arg (PEDEFR) as identified by mass spectrometry (MS) had no cytotoxicity on cells. PEDEFR at a high concentration (> 50 μmol/L) could enhance the phagocytosis of RAW264.7 cells. When the concentration was up to 100.0 μmol/L, the proliferation rate of spleen lymphocytes was 44.21% and reached up to 53.22% in the presence of concanavalin A. PEDEFR had an immunomodulatory effect on RAW264.7 cells. This study can provide an experimental basis for the development and utilization of immunoactive peptides derived from hazelnut protein.

Key words: hazelnut peptides, immunoactivity, isolation and purifiscation, structural identification