Improvement of meat tenderness by simultaneous application of high-intensity ultrasonic radiation and papain treatment

The present study aims to develop a novel process for improving meat tenderness. Three muscles were selected among five young Holstein bulls Longissimus lumborum muscles and were cut into 3 × 3 × 3 cm pieces. Samples were sonicated by ultrasonic probe (20 kHz) at power of 100 and 300 W for 10, 20, and 30 min both in the presence and absence of 0.1% papain enzyme solution. The effects of treatments were investigated on proteolytic activity, filtering residues, Warner–Bratzler shear force (WBSF), meat textural profile (TPA), and muscle microstructure. Application of enzyme, either singly or coupled with ultrasound significantly (P < 0.05) decreased the filtering residue, WBSF and textural parameters. The most proteolytic activity and the highest tenderness were obtained when the combined treatment was applied at ultrasonic power of 100 W for 20 min. Finally, the results showed that, combined treatment can be employed as a useful tool for the meat tenderization.