Abstract:Beef shank meat was taken as the research object, and the beef was braised by 3 braising methods, namely different vacuum braising, different ultrasonic power synergistic vacuum braising and different ultrasonic frequency synergistic vacuum braising, while the salt, moisture and weight changes of the braised beef were measured during the braising process to research the mass transfer law of ultrasonic co-vacuum braised beef. The results show that salt content variation increase with the increase of vacuum degree, ultrasonic power and frequency, moisture content variation and weight variation decreasing with the increase of vacuum degree, ultrasonic power and frequency. Kinetic parameters k1, k2 of the salt content variation of brined beef during braising process are in relation to vacuum degree, ultrasonic power and frequency. Under the conditions of vacuum degree -0.043 MPa, ultrasonic frequency of 28 KHz and power of 1000 W, the maximum value of effective diffusion coefficient De of salt content variation is 1.42×10-4 m2/s. The mass transfer driving force of 3 braising methods has a positive linear relationship with t0.5 /l, the correlation coefficients were all good. Vacuum braising and ultrasonic synergistic vacuum braising have significant effects on the microstructure of brined beef. Therefore, ultrasonic synergistic vacuum stewing has a significant effect on the mass transfer in stewed beef and can promote the mass transfer process. The best mass transfer conditions for ultrasonic synergistic vacuum stewing are vacuum degree -0.043 MPa, ultrasonic frequency 28 kHz, ultrasonic power 1000 W and ultrasonic time 30 min.
