A Novel Strategy for Authentication and Quantification of Porcine and Water Buffalo Hide Gelatin in Processed...

Pig skin and water buffalo hides were partially hydrolyzed to produce a heterogeneous mixture of polypeptides, known as gelatin, a commonly used food additive. Specific peptide markers were explored in the context of authentication and relative quantification of water buffalo hide gelatin (BHG) and porcine skin gelatin (PSG) via multiple reaction monitoring-mass spectrometry (MRM-MS). Tryptic gelatin peptides were separated and analyzed with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), and five unique peptide biomarkers were selected for BHG and PSG. Gelatin extraction from BHG and PSG spiked chicken meat patties (CMP) followed by LC-MS/MS MRM-MS revealed two unique bovine gelatin peptides of m/z 781.336 and 852.718 and three unique porcine gelatin peptides of m/z 774.570, 971.776, and 727.436. The optimized MRM-MS protocol was efficient in detecting BHG/PSG from spiked CMP up to 0.5% (w/w). Twenty-five commercial food samples were screened, among which four samples showed the presence of BHG and six samples showed the presence of PSG. The proposed LC-MS/MS MRM strategy provides an efficient and sensitive authentication and traceability of gelatin-containing highly processed food, bakery, and confectionery products.