Effect Of Ultrasonic-assisted Sodium Bicarbonate Curing On Chicken Quality

Curing was the most commonly used pre-treatment method for meat products,however the traditional curing method had too many limitations in the actual industrial production.There were serious shortcomings,such as slow curing rate,long time,low production and processing efficiency,low moisture content and so on.In order to solve the above problems,this paper studied the effect of ultrasoic-assisted sodium bicarbonate curing on chicken quality.The curing rate and edible quality of the chicken were determined,and the curing process was optimized.At the same time,the mechanism was preliminarily explored.The details results were as follows:1.The effect of different curing processes on curing rate and eating quality.In this part,traditional wet curing process(WC,6%salt)was used as a control group to study sodium bicarbonate(2%)assisted wet curing(NC)and sodium bicarbonate(2%)combined with ultrasonic curing process(NUC)on curing rate and eating quality of chicken breast meat(180d).The changes of curing rate and eating quality of chicken breast meat were studied by measuring the soaking yield,chloride content,pH,color,cooking loss and shearing force.The results showed that:The soaking yield and chloride content of the NUC group increased significantly(P<0.05),however the shearing force decreased significantly(P<0.05).NC and NUC groups showed higher pH(P<0.05)and lower cooking loss(P<0.05)compared with WC group;For color of chicken breast meat among three groups,the difference of L*value was not significant(P>0.05),b*value was decreased significantly(P<0.05).2.The optimization of sodium bicarbonate combined with ultrasonic curing process.In this part,the optimal conditions were determined by single factor and Box-Behnken experiments.The results indicated that the optimum conditions were as follows:sodium bicarbonate was 3.6%,ultrasonic time was 57 minutes and ultrasonic power was 450 W.In these conditions,the chloride content of chicken breast meat was measured as 1.676%.Three times verifications test showed the actual chloride content was 1.666%,which had 99.5%coincidence rate,compared with the model.However,the chloride content of the traditional wet-curing group was 0.936%after the same curing time for 57 minutes,which was 77.99%lower than that of NUC group.Therefore,the curing time was significantly shortened by NUC.3.Effect of different curing processes on microstructure.In this part,the myofibril fragmentation index(MFI),water distribution(Low-field nuclear magnetic resonance,LF-NMR),denaturation temperature of protein(Differential scanning calorimetry,DSC)and microstructure(Scanning electron microscope,SEM)of chicken breast meat(180d)cured by three different curing methods(WC,NC and NUC)were measured to analysis changes of microstructure and study mechanism of three different methods.The results showed:NUC had great damage to the muscle tissue of chicken breast and the highest MFI value(P<0.05);NUC could change the solubility and structure of protein resulted to promote the bound water change to free water,which could significantly reduce the relaxation time T20,T22 and T23 of chicken breast meat(P<0.05),and significantly increase T22(P<0.05).SEM showed that the NUC could not only enlarge the gap between the muscle fiber bundles and epimysium,but also form a lamellar gap in the endomysium in chicken breast.4.Effect of different curing processes on protein molecular force.In this part,the protein solubility,total sullhydryl content(T-SH),free sulfhydryl content(F-SH)and surface hydrophobicity(S0-ANS)of protein extract from chicken breast meat(180d)cured by three different curing methods(WC,NC and NUC)were measured to analysis changes of protein intramolecular force and explore mechanism of three different methods.The results showed:compared with WC group,total soluble protein content and protein content in curing solution of NUC group increased by 39.76%and 33.10%,respectively(P<0.05);T-SH content and S0-ANS value significantly decreased 26.28%and 39.34%respectively(P<0.05),however F-SH content significantly increased(P<0.05).NUC could increase the solubility of protein and change the high-level structure of protein,which folded and unfolded the protein and changed the protein intramolecular force,resulted in the changed of muscle protein structure and the increased of water binding capacity.