Sucrose Penetration and Functionality of Frozen Trout Muscle Affected by Tumbling Conditions

The effect of tumbling (vacuum pressure: 0, 50, 70 kPa; speed: 7, 14 rpm; time: 30, 60 min) on sucrose penetration into trout muscle was studied when trout chunks were tumbled with 4% (w/w) powdered sucrose. In addition, the cryoprotective action of sucrose in those tumbled muscle was evaluated at -20°C for 24 wk. Sucrose content, expressed as mg/cm2 of exposed area, increased linearly from the center to the periphery of muscle chunks. Vacuum during tumbling and extended tumbling time increased sucrose content of the center portion. Through 24 wk of frozen storage, all tumbling treatments had lower thaw loss and higher gel hardness and cohesiveness than the non-tumbled treatment. Tumbling with 70 kPa vacuum at 7 rpm for 30 min was optimum for sucrose penetration and muscle functionality.