Impact of Ultrasound Treatment on the Quality and Microstructure of Semitendinosus Muscle from Old Philippine Carabaos (Bubalus bubalis)

Commercially available carabeef (CB) is often tough as it is usually sourced from old carabaos retired from farm work. This study explored the feasibility of ultrasound (US) technology in improving CB tenderness, with the possibility of benefiting both the carabeef industry and consumers seeking nutritious, high-quality, and affordable meat. Semitendinosus muscles from Philippine carabaos (Bubalus bubalis) were treated using a water bath-type sonicator and analyzed for changes in meat quality. The effects of treatment duration (TD: 20, 30, 40 min) and water bath temperature (WBT: 5, 12, 25°C) on tenderness, pH, moisture content (MC), water-holding capacity (WHC), and color were assessed. Significant effects were detected in selected treatment combinations. Warner–Bratzler shear press results showed general improvement in tenderness across treatment durations. Color analysis revealed increased lightness (L*) and yellowness (b*) (p<0.05), with no change in redness (a*). TD had no significant effects on pH, MC, or WHC (p>0.05). Scanning electron microscopy revealed US-induced damage to connective tissue layers, including disrupted structure, cavities, and loss of integrity—observations that were associated with enhanced meat tenderness. This study demonstrates the potential of US technology in improving CB texture with minimal impact on other quality parameters. Our results support further optimization studies addressing industrial applications, process conditions, and animal traits.