Effect of pH-values on gelation properties of myosin extracted from high-pressure treated pre-rigor rabbit muscle

Myosin was extracted immediately from pre-rigor rabbit muscles (PRRMs) after high-pressure (HP) treatment (200 MPa, 25 °C for 15 s) to investigate the effect of pH (5.0, 5.5, 6.0, 6.5 and 7.0) on gel properties under the defined parameters. The water characteristics of the formed gel was modified as the pH altered. Improved water-holding capacity (WHC) was observed as the pH increased away from 5.5 and the highest value was reached at pH 7.0 (P<0.05). Assessment of rheological properties and secondary structures demonstrated that the thermal-induced aggregation of myosin after 50 °C was hindered at pH 6.5 and 7.0, and the unfolding of myosin conformational structures was intensified. Moreover, rapid exposure of buried amino groups in the temperature range between 40 °C and 70 °C occurred at pH 6.5 and 7.0, which contributed the formation of gel. These alternations give partial interpretation to the quality of gels obtained and verified the importance of monitoring the pH when applying HP treatment to the production of meat products.