The identification of three mammalian gelatins by liquid chromatography-high resolution mass spectrometry

High-performance liquid chromatography (HPLC) and linear-ion trap (LTQ)/Orbitrap high-resolution mass spectrometry were combined to systematically differentiate three mammalian gelatins including bovine-hide gelatin, porcine-hide gelatin and donkey-hide gelatin. Interestingly, hemoglobin was found only in the donkey-hide gelatin while not in bovine-hide gelatin and porcine-hide gelatin. In marker peptide determination for each individual gelatin, 28, 27 and 14 distinct peaks were detected to represent the bovine-hide gelatin, porcine-hide gelatin and donkey-hide gelatin, respectively. In the gelatin mixtures, all gelatins can be differentiated by their marker peptides. However, the number of detectable marker peptides in each gelatin decreased with reduced concentration of target gelatin in their mixtures. Under low content of target gelatin (less than 10%), 11, 15 and 5 marker peptides were detected in the gelatin mixture digests for bovine-hide gelatin, porcine-hide gelatin and donkey-hide gelatin, respectively. HPLC-LTQ/Orbitrap high-resolution mass spectrometry could be a promising technology to accurately identify bovine-hide gelatin, porcine-hide gelatin and donkey-hide gelatin for controlling the quality of food products added with gelatin.