Mass spectrometry detection of fraudulent use of cow whey in water buffalo, sheep, or goat Italian ricotta cheese

•A method for forensic detection of ricotta cheese adulteration is reported.•A method to detect extraneous cow whey proteins in ricotta cheese was developed.•β-Lactoglobulin and α-lactalbumin reveal the presence of cow whey in ricotta cheese.•Mass spectrometry exploits species-specific β-lactoglobulin and α-lactalbumin peptides.

Ricotta cheese is a typical Italian product, made with whey from various species, including cow, buffalo, sheep, and goat. Ricotta cheese nominally manufactured from the last three species may be fraudulently produced using the comparatively cheaper cow whey. Exposing such food frauds requires a reliable analytical method. Despite the extensive similarities shared by whey proteins of the four species, a mass spectrometry-based analytical method was developed that exploits three species-specific peptides derived from β-lactoglobulin and α-lactalbumin. This method can detect as little as 0.5% bovine whey in ricotta cheese from the other three species. Furthermore, a tight correlation was found (R2 > 0.99) between cow whey percentages and mass spectrometry measurements throughout the 1–50% range. Thus, this method can be used for forensic detection of ricotta cheese adulteration and, if properly validated, to provide quantitative evaluations.