EFFECTS OF HIGH-INTENSITY ULTRASOUND TREATMENT, STORAGE TIME AND COOKING METHOD ON SHEAR, SENSORY, INSTRUMENTAL COLOR AND COOKING PROPERTIES OF PACKAGED AND UNPACKAGED BEEF PECTORALIS-MUSCLE

Beef pectoralis muscles were removed at 24 h post mortem from nine ste ers, and samples were vacuum packaged and exposed to high-intensity ul trasound (20 kHz, 22 W/cm(2)) for 0, 5 or 10 min, then aged for 1, 6 o r 10 days before evaluation of purge and cooking losses, instrumental shear and color and sensory traits (Experiment 1). For Experiment 2, u npackaged beef pectoralis muscle samples from eight steers were subjec ted to ultrasonic cooking, boiling, convection cooking or ultrasound t reatment for 5 or 10 min followed by cooking in a convection oven. Nei ther duration of sonication nor storage of packaged pectoralis muscles affected (p > 0.05) storage purge or cooking losses, shear properties or sensory characteristics (Experiment 1). However, muscles receiving ultrasonic treatment showed tendencies for reduced peak force and tot al work to shear. Increased length of storage caused pectoralis muscle s to become more vivid red-orange colored (p < 0.05), whereas ultrason ic treatment caused muscles to become less vivid, less red and more or ange colored (p < 0.05). Ultrasonically cooked pectoralis muscles (Exp eriment 2) had lower (p < 0.05) cooking losses than muscles cooked by other methods. Both ultrasonic cooking and boiling were faster than co nvection cooking only, and ultrasound exposure follow ed by convection cooking. Additional studies are needed to verify the ability of ultra sound to promote improved cooking, sensory and shear properties of mus cle. (C) 1997 Elsevier Science Ltd.