**2. Materials and Methods**

## *2.1. Materials*

All reagents were of analytical grade. Peptides (22 dipeptides and 9 oligopeptides) were synthesized using a solid phase peptide synthesis method by Zhejiang Ontores Biotech Co., Ltd. (Hangzhou, China) with a purity of more than 90%. After cold-pressing for crude oil, defatted hazelnut flour (DHF) was obtained after a second solvent extraction to remove excess oil.
