The effect of electrical stimulation on beef tenderness, protease activity and myofibrillar protein fragmentation.

摘要: Abstract From six one-year-old White red bulls, one randomly assigned carcass half was subjected to high voltage electrical stimulation (HVES) at 1 h post morten (pm). Longissimus dorsi (LD) steaks from control (C) and stimulated sides (ES) were removed 24 pm, stored 4°C sampled 1, 6, 8 12 days pm. HVES caused an immediate fall of pH with about 0.5 units (Pτ 0.01), increase in temperature 1°C 0.05). lowered LD shear force values 0.05), both Sarcomere length not affected by stimulation, but cooking losses increased ES. Semi-quantitative SDS-PAGE, using BSA as internal standard showed the rate degradation several myofibrillar proteins be HVES. Levels 43-kDa peptide upon ageing higher ES 0.001). The level 30-kDa increases strongly early period faster It is striking that pm contain more 30 kDa suggesting activation calpain 1. levels 34- 35-kDa peptides, often considered tropomyosins, suggests these compounds are products. Troponin-T (TNT) degraded very fast period. 0.005) related tenderization (r=0.90). Irrespective HVES, titin a considerable extent (35%) during first 6 ageing, whereas nebulin filamin far less degraded. induced small activity calpastatin capacity remaining decreased significantly Ageing 2 activities 15% between no effect could detected. Total free cathepsin B L or Endogenous total proteolytical (measured release bound tryptophan TCA soluble peptides) substrate availability. We conclude significant tenderization, enhanced TNT formation 30- peptides. Tenderness improved within h, later on Part data suggest mortem due calpastatin-regulated activity. do role for cathepsins tenderization. To investigate relative importance various proteases meat conditioning situ measurement protease necessary, rather than measuring enzyme concentrations. Indeed, classical assays take into account regulation changing