ULTRASTRUCTURAL FINDINGS ON THE SKELETAL-MUSCLES OF PIGS FOLLOWING ULTRARAPID CHILLING IN THE INITIAL PHASE OF MEAT MATURATION

The purpose of this study was to show the structural alterations in the short-term frozen surface musculature of slaughtered pigs followed ultrarapid chilling methods. In muscles with normal glycolysis the short-term freezing of the musculature following ultrarapid chilling within 3 h 45 min post mortem led to cold shortening and in some areas to considerable changes in the transverse striation. The interstitial and interfibrillar spaces revealed severe oedema. The organelles showed, almost without exception, extreme vacuolar alterations and the cell membranes appeared fragmented. The non-frozen musculature of the more slowly chilled control group revealed similar changes but of a minor or less serious nature. In the muscle samples with accelerated glycolytic rates only minor differences were observed between the ultrarapidly chilled and the control musculature. Final evaluation of the effect of these chilling methods can only take place after studying the influence of the ultrastructural changes on the water binding capacity and tenderness of the musculature.