Study On The Effects Of Microwave On Gel Properties Of Chicken Breast Mince Meat

To explore the mechanism of microwave heating to improve the gel quality of meat, Byusing chicken breast as raw material, the gel quality of chicken breast mince irradiated bymicrowave for different time and under different load power density, and the changes ofheating and gel quality of chicken breast mince after adding NaCl were studied comparedwith the sample of water bath heating. Furthermore, the effects of microwave heating onphysical and chemical properties of myosin at different heating rate were also researched. Themechanisms of microwave heating for improving the gel quality of meat were investigatedcombined with the correlation analysis between the gel properties of chicken breast mince andphysical and chemical properties of myosin. The details are listed as follows:1. The cooking loss, hardness, chewiness and gel strength of chicken breast minceincreased significantly (P <0.05), and water holding capacity significantly decreased (P<0.05), with extending of microwave irradiating time. The color had a little change withirradiating time. The pH value was affected by temperature and showed a tendency todecrease and then increase afterward.2. The cooking loss, water holding capacity, color and pH value of chicken breast minceshoweda similar tendency as the result1, but the non-expressible water content was decreasedsignificantly (P <0.05) with the rising of loading power density. The hardness and gel strengthof chicken breast mince increased gradually, while the hardness and chewiness of the treatedsample under a power density of8W/g were significantlydecreased(P <0.05) due to thedestruction of gel network structure.3. Compared, the gel quality of chicken breast mince processed under microwave powerdensity of4W/g for140s had a similar quality with the sample heated by water bathing, whilemince irradiated under microwave power density of4W/g for200s had mucher higherhardness and gel strength (P<0.05). But the sample processed under microwave powerdensity of8W/g for140s had a poor quality and rough texture, which meane the sample wasoverheated by microwave.4.The addtion of NaCl resulted in the marked decrease in the heating rate and a linearincrease in temperature of chicken breast mince under microwave irradiation. The cooking loss and hardness of the chicken breast mince was significantly decreased(P <0.05), but waterholding capacity increased significantly (P <0.05) with the NaCl addition increase. Theflexible, cohesive and restorative had a significantly increase (P <0.05), the chewiness and gelstrength did not change obviously. Whiteness of the meat was gradually decreased, while thesaturation value was increased. Both of themchanged significantly(P <0.05).5. In the early stages of microwave heating at the heating rates of30and15℃/min, theturbidity of myosin solution was rapidly increased, and solubility decreased. While at the endof heating, there were few changes in turbidity and solubility and this indicated that themyosin denatured and aggregated completely. Surface hydrophobicity and disulfide contentincreasedwith the extension of the microwave heating time. The content of exposed sulfhydrylreached a maximum when the myosinsolution was heated to60~70℃by microwave, whichindicated that myosin molecules were unfolded and its conformation was changed whichpromoted to the exposing of hydrophobic group and free sulfhydryl group when thetemperature was between30~60℃. The content of total free sulfhydryl group had nosignificant changes, and the tendency was different from the declining trend by traditionalwater bath heating.6. The results of SDS-PAGE gel electrophoresis analysis showed that the degradationand aggregation of myosin strip were occurred duringmicrowave heating.7. According to the correlation between the gel properties of chicken breast mince andphysical and chemical properties of myosin, water holding capacity of mince and total freesulfhydryl groups of myosin had a significant negative correlation (P <0.05), while hardnessand turbidity and exposed sulfhydryl and the total free sulfhydryl groups of myosin had asignificant positive correlation (P <0.05). But there was a significant negative correlationbetween the solubility of myosin and hardness(P<0.05). Chewiness and gel strength had asimilar trend as the hardness values; Flexibility of the chicken breast mince had a significantpositive correlation with surface hydrophobicity of the myosin (P <0.05), and a highlysignificant positive correlation with the disulfide bond (P <0.01).