Myofibrillar protein degradation of carp (Labeo rohita (Hamilton)) muscle after post-mortem unfrozen and frozen storage

The degradation of myofibrillar proteins of rohu carp (Labeo rohita (Hamilton)) muscle was analysed after post-mortem storage. Muscle fillets were kept either unfrozen at 2 degreesC for up to 15 days or frozen at -80C or -20 degreesC for up to 6 months. A co-ordinated histochemical, biochemical and electrophoretic study showed a differential response of the carp muscle, revealing clear degenerative/degradative changes specific to the post-mortem storage temperatures. The myofibrillar protein fractions, namely myosin light chains and Lu-actinin, showed degradative changes during the above storage conditions, whereas other protein fractions in the high-molecular-weight range fragmented to give lower-molecular-weight proteins. The importance of the post-mortem storage temperature for controlling the degradation of the myofibrillar proteins was emphasised. This is the first report on this popular fish species, known for its culinary importance, showing that specific protein fractions of the myofibrils degrade during post-mortem storage. (C) 2001 Society of Chemical industry.