Bacterial control and structural and physicochemical modification of bovine Longissimus dorsi by ultrasound

•The influence of ultrasound intensity, sonication time, and storage time on beef properties was studied.•Application of ultrasound did not modify luminosity, redness or yellowness of beef.•Degradation of the color of meat was influenced by the intensity of sonication and the storage time.•The interfibrillar areas increase in meat samples treated with ultrasound at 16, 28 and 90 Wcm−2.•Ultrasound reduces significantly the growth of mesophilic, psychrophilic and coliform bacteria. A multifactorial study to evaluate the effect of three ultrasound intensities (16, 28 and 90 Wcm−2), two sonication times (20 and 40 min), and two storage times (0 and 7 days at 4 °C) on physicochemical properties, microbiological counts, and microstructure of bovine Longissimus dorsi was performed. The results showed that ultrasound (US) did not modify luminosity (P = 0.42), redness (a*, P = 0.45), or yellowness (b*, P = 0.94). However, the hue angle increased with US treatment and during storage (P = 0.04), showing an important degradation in the color of meat treated with 16 Wcm−2. The pH and shear force decreased during storage at 4 °C (P = 0.01). Although US did not have any significant effects on the tenderness of the meat, the interfibrillar areas increased drastically in samples treated with 16, 28 and 90 Wcm−2 (P