No study has yet been undertaken to differentiate between the fragmentation
by papain and the aging of myofibrils in muscle. In situ rod formation
by papain at 2°C was used to invstigate and compare if such fragmentation
occurs during on-carcass aging at 2°C, and the changes in protein concentrations
of myosin fraction before and after the ethanol fractionation were
measured in addition to the measurements of viscosity and optical rotatory
dispersion (ORD) and electrophoresis in sodium dodecylsulfate polyacrylamide
gel (SDS-PGE) of the ethanol-treated protein fraction. We have directed
our efforts toward the clarification of the decisive incongruity between the
effects of papain and aging on meat tenderness.