Many cheeses are created with proteolysis via added enzymes, bacteria and molds. Therefore, cheese represents an excellent source from which novel bioactive peptides may be found. We are profiling the peptides in a variety of cheeses (including Casu Marzu, Stilton Blue, Taleggio, and Mimolette) by mass spectrometry (ESI-Orbitrap MS/MS). Collaboration with Dr. Daniela Barile and Randall Robinson has enabled the identification of thousands of endogenous peptides from each of these cheeses. Next, we plan to explore these cheese peptides for beneficial functions. The cheeses used for this study represent a diverse variety of milk types and ripening conditions, which should provide a rather unique collection of compounds from which bioactivities can be mined.