Mass Transfer Law Of Ultrasonic Assisted Vacuum Stewed Beef And Its Effect On The Quality Of Stewed Beef

Ultrasonic meat processing and vacuum meat processing have the characteristics of reducing processing time and keeping good quality structure and nutritional value of meat products.In this paper,beef tendon meat was used as raw material to explore the mass transfer law under ultrasonic assisted vacuum stewing and its influence on the quality of stewed beef,and the relevant experimental data of ultrasonic assisted vacuum stewed beef were obtained.The verification results are as follows:（1）Taking beef tendon meat as the research object,beef was stewed in three ways:different vacuum stewing,different ultrasonic power assisted vacuum stewing,and different ultrasonic frequency assisted vacuum stewing.The changes of salt,moisture and weight of beef were measured during the stewing process,and the mass transfer law of ultrasonic assisted vacuum stewing beef was studied.Ultrasonic vacuum brine boiling and vacuum brine boiling can significantly promote mass transfer.△M_t^{C l}increases with the increase of vacuum,ultrasonic power and frequency,△M_t^wand△M_t^odecrease with the increase of vacuum,ultrasonic power and frequency.The kinetic parameters k₁and k₂of△M_t^{C l}of stewed beef were related to vacuum degree,ultrasonic power and frequency;Under vacuum degree of-0.043 MPa,ultrasonic frequency of 28 k Hz and power of 1000 W,the effective diffusion coefficient De of△M_t^{C l}is the maximum,which is 1.42×10^-4m²/s,the mass transfer driving force of three brine boiling modes has a good linear relationship with t^0.5/l.Vacuum stewing and ultrasonic assisted vacuum stewing had a significant effect on the microstructure of stewed beef.Therefore,ultrasonic assisted vacuum stewing has a significant effect on the mass transfer in stewed beef and can promote the mass transfer process.The optimal mass transfer conditions for ultrasonic assisted vacuum stewing are vacuum degree-0.043 MPa,ultrasonic frequency 28 k Hz,ultrasonic power 1000 W and ultrasonic time 30 min.（2）The flavor of stewed beef was detected by ultrasonic vacuum stewing,ultrasonic stewing,vacuum stewing and atmospheric pressure non ultrasonic stewing.The amino acid contents of ultrasonic vacuum brine cooking,ultrasonic brine cooking,vacuum brine cooking and atmospheric pressure non ultrasonic brine cooking were 39.15,39.57,38.33 and 38.48 g/100g respectively.51 kinds of volatile flavor substances were found in ultrasonic vacuum brine cooking,48 kinds of ultrasonic brine cooking,47 kinds of vacuum brine cooking and 42 kinds of atmospheric pressure non ultrasonic brine cooking.The volatile flavor substances contents were 25.96%,20.12%,16.72%and 15.99%respectively.There were significant differences in the flavor of the four treatment groups according to the electronic tongue evaluation,According to the sensory evaluation of fuzzy mathematics,the scores of ultrasonic vacuum stewed beef were 96.08,91.56,94.04 and 83.63 respectively.Its flavor,taste and appearance were more acceptable.（3）The quality structure of stewed beef stewed in ultrasonic vacuum,ultrasonic,vacuum and atmospheric pressure without ultrasonic after cooling to room temperature.The four brine cooking methods can significantly affect the secondary structure of protein.Irregular curl was not detected in ultrasound group,vacuum group and atmospheric pressure non ultrasound groupα-Spiralβ-Corner andβ-Fold,whereα-The helix content is the largest,and the protein structure of ultrasonic vacuum group is mainlyβ-Folding,accounting for 32.31%,α-Spiral 24.54%,β-Angle 23.30%,irregular curl 19.84%;Compared with normal pressure non ultrasonic stewing,the shear force of stewed beef under ultrasonic vacuum stewing was significantly reduced;the L value of stewed beef increased significantly,the a^*value decreased,and the yellowness value b^*had no significant difference;The cooking loss of stewed beef by ultrasonic vacuum cooking was reduced and the centrifugal water holding capacity was enhanced;The results of water distribution showed that the relaxation time of T₂₂moved to a shorter direction,the unfit flowing water increased significantly,and the ability of bound water increased;Ultrasonic vacuum improved the texture characteristics of stewed beef:hardness and chewability decreased slightly,cohesion and elasticity increased significantly.（4）Using ultrasonic vacuum,ultrasonic,vacuum and atmospheric pressure non ultrasonic stewed beef,the safety indexes were tested after being stored at 4℃for 2 days.Ultrasonic vacuum treatment can effectively inhibit the growth and reproduction of microorganisms.The total number of colonies in ultrasonic vacuum stewed beef decreased significantly to 2.57×10⁴CFU/g,lower than of ultrasonic brine cooking,vacuum brine cooking and atmospheric pressure non ultrasonic brine cooking 3.78×10⁴、3.26×10⁴、3.92×10⁴CFU/g.Compared with normal pressure and no ultrasound,the TVB-N,nitrite,TBARS value and heterocyclic amine content of stewed beef in ultrasonic vacuum cooking,ultrasonic cooking and vacuum cooking decreased significantly（P<0.01）.The content of Met Mb in ultrasonic vacuum stewed beef was significantly lower than that in ultrasonic stewed beef,vacuum stewed beef and normal pressure non ultrasonic stewed beef.