Ultrasound as a potential process to tenderize beef: Sensory and technological parameters

In this study, the effects of high intensity ultrasound (HIU), applied after storage, on the physical, microstructural, and sensory characteristics of beef were evaluated. Samples of four beef m. Longissimus dorsi muscle were stored in vacuum at 4 °C for 0, 7 or 14 days and then ultrasonicated (40 kHz, 11 W/cm²) for 60 min. Beef stored for 7 d prior to ultrasonication displayed increased pH and luminosity, reduced redness and saturation value, higher hue angle, and variable changes in water holding capacity. Shear force of sonicated meat was lower than that of control samples at all storage times. HIU also increased the tenderness and fragmentation of meat (P < 0.05) measured by texture profile analysis. The microstructure of sonicated meat showed a visible reduction in the size of fascicles, greater interfibrillary spaces, and thinner endomysium. These effects were enhanced with the storage of meat previous to HIU treatment. Meat stored for 14 d and then treated with ultrasound was perceived to have a more intense fresh meat smell and oily flavor (P < 0.05). However, it was also perceived to be a paler grayish brown color compared to control samples stored for the same duration. Ultrasonicated meat also presented a greater intensity of metallic taste (P < 0.05) and a more tender and moist texture (P < 0.05). Overall, application of HIU of meat after meat was stored affects textural and microstructural properties and accelerates aging without negative impacts on other technological and sensory attributes. Therefore, HIU application after storage has potential as a safe method for tenderizing bovine meat when handled under the conditions in this study.