Proteolysis as a function of distance from surface to centre in a smear-ripened Irish farmhouse cheese

This study focused on proteolysis in an Irish farmhouse smear-ripened cheese by serial slicing (0.41 mm/slice) the first 2 cm from surface towards the centre of the cheese. Urea-polyacrylamide gel electrophoretograms confirmed higher proteolysis in the outer layers than at the centre. Free amino acid (FAA) analysis confirmed decrease in proteolytic activity from surface to centre. Peptides produced at depths 0.41 mm and 20.5 mm were 720 and 427 from αs1-casein; 691 and 337 from αs2-casein; 807 and 453 from β-casein; 180 and 109 from κ-casein. The study confirms higher proteolytic activity at surface due to action of enzymes of the smear microbiota, than at the centre of cheese and identified the agents responsible for production of many peptides.