Use of the Cd-ninhydrin reagent to assess proteolysis in cheese during ripening

Summary A new method for monitoring the terminal stages of proteolysis in cheese, i.e. the formation of free amino acids, using the Cd-ninhydrin reagent is reported. The assay was very specific for free amino acids and may be performed on citrate-soluble, water-soluble or phosphotungstic acid-soluble fractions of cheese, but not on trichloroacetic acid-soluble extracts; water-soluble extracts were chosen for routine analysis. Application of the...