The effect of ageing on the water-holding capacity of pork: role of cytoskeletal proteins

The water-holding capacity (WI-IC) of pork decreases post-mortem but has be en shown to increase during subsequent ageing. In order to test a hypothesi s that water-holding capacity increases during ageing due to degradation of the cytoskeleton, WHC was followed 10 days post-mortem and related to the extent of proteolysis of cytoskeletal proteins. A fast method for measuring WHC in small meat samples was developed by the use of centrifugation. The WHC of fresh pork decreases in the first part of post-mortem storage after which it increases to the level of 1 day PM. No changes in total water cont ent of the meat were observed which could explain changes in WHC during age ing. Vinculin and desmin degrade gradually during ageing while talin degrad es rapidly. These observations are consistent with the hypothesis that degr adation of the cytoskeleton slowly removes the linkage between lateral shri nkage of myofibrils and shrinkage of entire muscle fibres, so removing the force that causes flow into the extracellular space. Inflow of previously e xpelled water is then possible, so increasing WHC as observed in later peri ods of storage. (C) 2001 Published by Elsevier Science Ltd. All rights rese rved.