The Researches Of The Extraction Of Myofibrillar Proteins Of The Chicken Chest Meat And The Gelation Properties

Chicken was rich in protein.The meat proteins could give meat products particular flavor, tast and nutrition.Their functional properties such as water-holding capacity,gelation-forming properties played an important part in the final quality of the products.Myofibrillar proteins accounted for 40%-60%among meat proteins,and was a kind of structural proteins which had important biological function.They could take part in sarcous shrinkage,affected sarcous tenderness and hadnearly relation with sarcous rheological properties such as gumminess, adhesive force,springiness,texture.Myofibrillar proteins were the most important salt_soluble protein and played a vital role in the formation of thermal induced gelation and the functional properties of chicken salt_soluble proteins.The three-dimensional network structure of Myofibrillar proteins thermal induced gelation helped stabilize fatty and water,which improved the functional characteristics of chicken products.The extraction of Myofibrillar proteins from the chicken chest meat was introduced,the effects of different pH on myofibrillar proteins content and the gelation properties of Myofibrillar proteins were studied in this paper,I carried on the study in order to optimize the technics and provided theoretical references for improving the quality of chicken products.The followings were the main studying results:1.Myofibrillar proteins preparation,content measured and identifition:the amount of Myofibrillar proteins became large with increasing pH,the maximal content of myofibrillar proteins was 69.74%in pH7.0.Sodium dodecyl sulfate-polyacrylamide gelation electrophoresis (SDS-PAGE)analysis showed that myofibrillar proteins were mainly made up of myosin,actin,actosin and some other small molecular proteins.2.Ionic strength(P＜0.01)and pH(P＜0.1) had evidently influence on the gelation water-holding capacity and The influential order was:Ionic strength＞pH.The optimum extracting conditions were Ionic strength 0.6 and pH7.0.The gelation which was prepared at this condition had the maximal gel water-holding capacity(81.5%),gel hardness(46g) and gel gumminess(28.83g).Gel springiness changed random,the minimal gel springiness was 0.01mm at Ionic strength 0.4and pH6.0 and the largest Gel springiness was 3.39mm at Ionic strength 0.6 and pH6.0.3.Effects of polyphosphates on gel water-holding capacity,hardness,gumminess and springiness:By using L₁₆(4⁵) orthogonal experiment,Sodium pyrophosphate(SP)(P＜0.1),Sodium triphosphate(STP)(P＜0.01),Sodiumhexame taphos-phate(HMP)(P＜0.025) affected evidently on gel water-holding capacity of salt-souble proteins,The influential order was:STP＞HMP＞SP.Polyphosphates could improve gel water-holding capacity of salt-souble proteins observably from1.5%to 99.86%.SP(P＜0.01) affected evidently on hardness and gumminess of salt-souble proteins,SP (P＞0.1),STP(P＞0.1)and HMP(P＞0.1)affected indistinctively on springiness of salt-souble proteins,when the ratio of SP,STP and HMP was 1:3:3,hardness(234g),gumminess(184.8g) and springiness(3.61mm) of salt-souble proteins were all the best and improved ordinal by 188 g,205.97 g,0.22mm than those of no polyphosphates。4.Effects of carrageenan on gel water-holding capacity,hardness,gumminess and springiness:when carrageenan concentration was more than 0.6%,carrageenan could improve gel water-holding capacity of salt-souble proteins observably.when carrageenan concentration was lower than 0.6%,hardness of salt-souble proteins became small gradually.The more the adding dose of carrageenan was,the smaller the gelation hardness,when carrageenan concentration was more than 0.6%,gelation hardness became big observably,gelation hardness first became big then small with increasing of the adding dose of carrageenan.when the adding dose of carrageenan did not change,the bigger the carrageenan concentration was,the bigger the gelation hardness was.The optimum gelation hardness was 297g when carrageenan concentration was1.5%and the volume ratio between carrageenan and salt-souble proteins was 0.8.when carrageenan concentration was lower than 0.9%,gumminess of salt-souble proteins became small gradually with increasing of the adding dose of carrageenan,when carrageenan concentration was bigger than 0.9%,gumminess of salt-souble proteins became big gradually with increasing of the adding dose of carrageenan,when the adding dose of carrageenan didn't change,the bigger the carrageenan concentration was,the bigger the gelation gumminess was. The optimum gelation gumminess was 170.23g when carrageenan concentration was1.5%and the volume ratio between carrageenan and salt-souble proteins was 1:1.when carrageenan concentration was 0.3%,springiness of salt-souble proteins became little with increasing of the adding dose of carrageenan,when carrageenan concentration was 0.6%, gelation springiness reduced nearly in line with increasing of the adding dose of carrageenan. when carrageenan concentration was not lower than 0.9%,gelation springiness first became big then small and later big,with increasing of the adding dose of carrageenan.The optimum gelation springiness was 3.33mm when carrageenan concentration was1.5%and the volume ratio between carrageenan and salt-souble proteins was 0.6.5.Effects of Mg²⁺ on mixed gel water-holding capacity,hardness,gumminess and springiness of carrageenan and salt-souble proteins:Mg²⁺ had no evident influence on mixed gelation water-holding capacity,but could evidently reduced mixed gelation hardness and springiness.mixed gelation gumminess was the best when carrageenan concentration ranged from 0.6 to 0.9 and the volume ratio between carrageenan and salt-souble proteins ranged from 0 to 0.6.6.Effects of soybean protein isolate(SPI) on gel water-holding capacity,hardness,gumminess and springiness:gel water-holding capacity,hardness,gumminess and springiness were all small when added SPI to salt-souble proteins,this indicated that the network structure of salt-souble proteins proteins thermal induced gelation was more exquisite and compacter than that of SPI gelation.