Gelatin, a partial hydrolysis result of animal collagen, has been commonly utilized in the Indonesian food industry, yet a strict regulation regarding the origin of gelatin is applied due to religious concerns. Therefore, a procedure that identify the origin of gelatin is required. The purpose of this research was to estimate peptide biomarkers using a bioinformatics approach that applicable to identify different gelatin sources by means of mass spectrometry. Collagen sequences from cattle, pigs, chickens, and fish were collected from the UniProt database. The sequences were in silico digested using trypsin in PeptideMass software. The resulting peptides were filtered following the criteria for mass spectrometry. Trypsin digestion produced a high number of specific peptides. Some of the specific peptides has been identified and it has potential to distinguish the animal derived gelatin.