Purification and characterisation of α-glucosidase inhibitory peptides from defatted camellia seed cake

Summary Enzymatically derived peptides from different proteins have displayed the potential to provide health benefits. Present research aims to obtain the functional peptides and improve the economic value of camellia seed cake via enzymatic hydrolysis. Camellia seed cake protein hydrolysates (CSCPH) prepared with alcalase demonstrated higher α-glucosidase inhibitory activity. After ultrafiltration, the α-glucosidase inhibitory activity of different components was compared. The component (CSCPH-IV) with the highest activity was selected for further separation and purification. The peptides were purified using reverse-phase high-performance liquid chromatography (RP-HPLC) twice and identified as GHSLESIK, GLTSLDRYK and SPGYYDGR by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Subsequently, the preliminarily inhibitory effect of these peptides on α-glucosidase activity was demonstrated by the molecular docking model. These results showed that three novel peptides isolated from the hydrolysates of camellia seed cake have the potential to be used as anti-diabetic compounds for the development of functional foods.