Protein oxidation in processed cheese slices treated with pulsed light technology

The effect of pulsed light technology on protein oxidation was studied in sliced processed cheese by measuring the protein-bound carbonyls with a spectrophotometric DNPH assay. Bovine serum albumin was also tested as a protein standard. Fluences of 0.7, 2.1, 4.2, 8.4 and 11.9 J/cm2 were applied to vacuum-packaged cheese slices and to an aqueous solution of the protein. Treatments up to 4.2 J/cm2 did not promote protein oxidation immediately after flashing either in cheese or in the standard. Samples treated with 8.4 and 11.9 J/cm2 showed significantly higher carbonyl amounts than non-treated ones. Protein oxidation increased along cheese storage at 4 °C, and differences among treatments remained. Further studies on the sensory properties will be needed to clarify the impact of pulsed light on processed cheese quality.