Standardized analytical method for authentication of chickpea protein concentrates using targeted proteomics and high-resolution mass spectrometry

Chickpea protein concentrates are increasingly used in plant-based and allergen-friendly food applications due to their nutritional and functional properties. However, the growing demand for chickpea protein has heightened concerns over economically motivated adulteration and mislabeling. To address this, we developed a high-resolution, targeted proteomics workflow for authenticating chickpea protein concentrates using LC-QTOF-MS/MS. Unlike broader spectral fingerprinting approaches such as spectroscopy techniques or nitrogen quantificaiton, this method enables peptide-level specificity, allowing for robust detection in complex food matrices. A systematic peptide identification pipeline, employing both in-gel and in-solution trypsin digestions, led to the discovery of two chickpea-specific legumin-derived peptides (GFEETIC(alk)TAR and ALIVPQNFAIAAK) that were consistently detectable and unique among common plant, dairy, and other adulterant sources. To the best of the knowledge of the authors, these are the first peptides suggested for use of chickpea adulteration detection by any proteomics techniques. Detection remained reliable even in commercial chickpea pasta samples containing about 20 % total protein. This reproducible, targeted approach provides enhanced specificity and transferability, representing a practical and sensitive method for chickpea protein authentication in both regulatory and industrial settings.