Validation and theoretical justification of an LC-MS method for the animal species specific detection of gelatin

Collagen is the most abundant protein family in mammals. Commercial edible gelatins are often produced from bovine and porcine skin and bone and consist mainly of partially hydrolyzed collagen type 1. The gelatin industry would benefit from a sensitive and reliable species detection method to unambiguously demonstrate species authenticity of their products. PCR and ELISA could in principle be used for this purpose. However, for gelatin, problems associated with false-positive and false-negative results, inconsistencies and low reactivity of commercially available kits have been observed with regard to ELISA and PCR methods. Therefore we developed a selective bottom-up LC-MS methodology for quantitative gelatin species determination with a lower limit of quantification of 0.05%. The present article describes the validation of this method, which was performed according to Good Laboratory Practice, and the theoretical justification for bovine and porcine target selection. The validated method can be used to determine the purity of gelatin batches with regard to bovine and porcine constituents.