61. Discoloration in New Zealand Cheddar Cheese. Muddy, Bleached and Pink Defects. II. Biochemical Investigations

Abstract

The evidence of pH and catalase tests confirms the view that mould growth is closely associated with the production of discoloration in cheese.The pink discoloration appears to be the result of acids acting upon the annatto colour.Evidence available from observations and other sources, suggests that the bleaching is chemically a reduction in which changes in the fat play a part.The muddy or dark discoloration appears to be produced by enzymes (including possibly tyrosinase) which diffuse into the cheese from centres of mould growth and act upon chemical substances present in mature cheese.