The effects of low frequency ultrasound on exudate yield, breaking strength, cooking yield, water-holding capacity, color, and muscle microstructure were investigated by exposing pieces of lean muscle to slow tumbling and low frequency ultrasonic waves. Results indicated that beef rolls exposed to low frequency ultrasound without added salt were superior in breaking strength and cooking yield to those tumbled with neither ultrasound nor salt and were comparable in breaking strength, cooking yield, exudate yield and water-holding capacity to those tumbled with salt and no ultrasound exposure. Furthermore, the beef rolls exposed to ultrasound and no salt were superior in color to those to which salt was added. Low frequency ultrasound caused muscle fiber disruption and separation of up to approximately 1 cm in depth in muscle micro-structure in the pieces of lean muscle.