The effect of lactic acid marination at 5 degrees C on post mortem changes in breast muscle pectoralis major of spent layer Tsaiya duck was studied. 2. Myofibrils were prepared from 0.1 M and 0.2 M lactic acid marinated muscle and control (non-marinated samples) sampled at 0, 1, 3, 7 and 14 d post mortem. 3. Changes in myofibril fragmentation index (MFI), myofibrillar proteins and Z-line structure were examined. 4. Marination of duck breast muscle in lactic acid at 5 degrees C enhanced fragmentation of myofibrils and degradation of myofibrillar proteins and Z-line structure as compared to control samples. 5. In summary, lactic acid marination at 5 degrees C can accelerate the post mortem degradation of myofibrils in Tsaiya duck breast muscle.
