The Study Of Water-holding Capacity And Protein Functional Properties Of Cold Fresh Yak Meat

The loss of juice of muscle has a serious impact on production and consumption during the storage and processing.The yak meat was selected for experimental material with different water-holding capacity during postmotern aging in this experiment,the juice loss,protein changes,as well as the MP foamability,foam stability,emulsifying activity and emulsifying stability,gel water-holding capacity and gel texture features,chemical reaction and dynamic rheology in the process of MP gel thermal induced were determined,the variations were evaluated between water-holding capacity and functional properties result of water-hoiding capacity during postmotern aging,In order to realise the juice loss reduction effectively and water-holding capacity mechanism for further research as well as provide basic data for heat treatment food.The main conclusions are as follows: 1?The variation of juice loss,p H and color in different water-holding capacity yak meat were confirmed.The variation of p H,CIE L*,CIE a* and juice loss were significant difference(P<0.05),and CIE b* was not significant(P>0.05)in different water-holding capacity yak meat during postmotern aging.The p H decreased first then increased,the highWHC samples dropped to the minimum5.57 at 3d,while the low-WHC samples dropped to the minimum 5.36 at 1d,and was lower1.27% than high-WHC samples.the color CIE L* and CIE a* have a reduction after increased and increased continuously,CIE b* increa sed first then decreased,CIE L* was higher7.03% with low-WHC samples than that of high-WHC group,CIE a* was less 12.3% than high-WHC group,the variation of the juice loss also has a certain regularity,the pressure loss and cooking loss increased first then decreased,drip loss and storage loss increased continuously,compared with high-WHC group,pressure loss,cooking loss,drip loss,storage loss low-WHC samples was higher 14.19%,9.2%,0.36%,0.54%,respectively.2?The protein degeneration and degradation were responsible for juice loss during postmoter n aging.Protein solubility was negatively correlated with juice loss by variation of protein sol ubility and in combination with relevant analysis,in which the sarcoplasmic protein solubility was negatively correlated with drip loss significantly,and the correlation coefficient was-0.624,-0.628 between high and low-WHC groups.whereas SDS-PAGE profile suggested that de gradation of desmin(27 k Da)was obvious,and discovered obvously at5 d and 3d during post motern aging between high and low-WHC groups.3?The effect of water-holding capacity on MP molecular and physicochemical properties an d variation obout themselves were confirmed during postmotern aging.The variation of MP molecular and physicochemical properties had a regular trend in different water-holding capac ity yak meat during postmotern aging,and reached significant difference between the two gro ups at different aging time.MP foamability,emulsifying activity and emulsifying stability dec reased first then increased,MP turbidity,foam stability decreased first then increased,the surf ace hydrophobicity increased continuously,with temperature increasment,the storage modu lus(G')increased first then weaken and increased rapidly again,and reached maximum at agi ng3 d,and aging5 d so on.MP foamability,foam stability,emulsifying activity,emulsifying st ability and G ' from high-WHC group were higher 29.21%?13.77%?17.64%?12.94%?52.48% than that of low-WHC group,and MP turbidity,surface hydrophobicity were lower 14.96%,18.37% than that of low-WHC group.4?The effect of water-holding capacity on yak meat MP heated gel properties and variation obout themselves were confirmed during postmotern aging.MP heated gel properties in different water-holding capacity yak meat during postmotern aging were significant difference at different aging time,gel water retention,elastic decreased first then increased,gel hardness,adhesiveness and chewiness decreased first then increased,MP gel water retention,hardness and elasticity from high-WHC group were higher 6.71%,24.66%,1.99% than that of low-WHC group,and MP adhesiveness and chewiness were lower 20.85%,27.78% than that of low-WHC group.the chemical reaction,there was a significant differenc between high and low-WHC groups,MP heated gel were higher than that of highWHC group at different heat induced temperature and different aging time.The main force of MP gel system from the the electrostatic interaction(initial state of the initial sol(25-35 ?))into hydrophobic interactions.