Cathepsin B, D, H and L activities in the processing of dry‐cured ham

Abstract The activities of cathepsins B, D, H and L have been assayed at various stages in the slow processing (15 months) of dry‐cured ham. Cathepsins B, H and L showed low recovered activity (5–10% of the initial activity) at the end of the process. However, cathepsin D almost disappeared after 5–10 months. Water‐soluble protein extractability decreased throughout the process while myofibrillar protein extractability was constant. There was a progressive disappearance of myosin heavy chain, myosin light chains 1 and 2, and troponins I and C, a marked increase of three breakdown products with molecular weights of about 150, 95 and 16 kDa and some minor products in the ranges 50–100 kDa and 20–45 kDa. Cathepsins B and L could be particularly active in the observed proteolysis which had a special relevance when the drying started. Actin, actinin, troponin T and tropomyosin did not seem to change.