Method for identifying gelatin source in donkey-hide gelatin product

The invention discloses a method for identifying a gelatin source in a donkey-hide gelatin product. The method comprises the steps of 1, pretreating the donkey-hide gelatin product, specifically, adding bovine gelatin and pig gelatin into an aqueous solution of the donkey-hide gelatin product; carrying out solid-liquid separation, filtering, and freeze-drying the filtrate; 2, conducting sample enzymolysis, specifically, treating the freeze-dried sample with an SDT buffer solution, a UA buffer solution, IAA and an NH4HCO3 aqueous solution, finally adding an NH4HCO3 aqueous solution containing trypsin, and centrifuging to obtain a gelatin polypeptide solution; 3, carrying out high performance liquid chromatography-mass spectrometry detection, specifically, loading the gelatin polypeptide solution into an Easy nLC-Orbitrap Fusion Tribrid mass spectrometer for detection; and 4, performing data analysis, specifically, matching and analyzing the obtained mass spectrogram by adopting MASCOT software, setting the dat