Isolation, Purification and Structure Identification of Salty Peptides from Wheat Gluten

Abstract

The salty enzymatic hydrolysate of wheat gluten was desalted and fractionated into four fractions (F1–F5). F4, which had the highest salty taste and proportion of peptides with molecular mass below 1 000 Da among these fractions, was further fractionated by Sephadex G-15 gel filtration chromatography into five subfractions (P1–P5). Among these subfractions, P2 was found to have the highest content of salty peptides and the strongest salty taste. By liquid chromatography tandem mass spectrometry (LC-MS/MS), the amino acid sequences of P2 were identified as PFGQQ, PFSPQ, QPFP, PDFP and FDDP, with molecular masses of 576.28, 575.28, 488.25, 475.22 and 493.21 Da, respectively. The results provide a theoretical basis for the development of salty peptides from gluten protein.

Keywords

• gluten proteins; salty peptides; purification; identification; amino acid sequences