Spotting the differences between milks from different animal species

Milk proteins from different species (cow, goat and sheep) generated distinct RP-HPLC protein profiles and contained peptides unique to either cow milk or sheep and goat milk that can be detected by nLCMS. Two peptides were identified from β-Lg that can be used to confirm cow (TPEVDDEALEK125-135 and LSFNPTQLEEQCHI149-162) or sheep milk (TPEVDNEALEK125-135 and LAFNPTQLEGQCHV149-162). The developed RP-HPLC method could be used as a rapid scanning tool to profile protein fingerprints of milk from different species for milk differentiation and identification. The nLC-MS method could be used to detect adulteration and quantify the level of adulteration down to a limit of 1%.