The effect of glycation on the identification of characteristic tryptic peptides from porcine gelatin

High-performance liquid chromatography and linear-ion trap/Orbitrap high-resolution mass spectrometry (HPLC-LTQ/Orbitrap MS/MS) was used to trace the origin of porcine gelatin under different glycation reaction times. With the extension of the glycation reaction time, the characteristic peptides of porcine gelatin gradually decreased, indicating that the glycation reaction would have an impact on the identification of porcine gelatin. In addition, compared with the porcine gelatin theoretical characteristic peptide database, it was found that the number of characteristic peptides of porcine gelatin in the glycation reaction of 0, 24, 48, 72 and 96 h were 39, 84, 82, 73 and 70, respectively. Among them, 33 characteristic peptides did not change with the extension of glycation time. Compared with our previous research, 9 characteristic peptides were found to be common to porcine gelatins under the different food processing conditions. These stable common characteristic peptides could be used as an important basis for porcine gelatin traceability with high accuracy.