Effect Of Rigor Mortis And Technology On Gel Functionalities Of Surimi From Bighead Carp

Post mortem changes are important factors concerning the bighead carp processing, which can influence the gel properties by changes of salt-soluble proteins. Salt-soluble protein is the main protein in fish muslce. The gel properties of salt-soluble proteins can effect the texture and water holding capacity of surmi product which is influenced by many factors, such as pH, ionic strength, washing methods and times, heating temperature. Muscle of bighead carp is used as the material to analyze the effect of rigor mortis and pH on the gel strength, water holding capacity, cooking loss and dynamic viscoelastic properties of surimi from bighead carp. Finally, the gelation condition of bighead carp is optimized with reponse surface. The contents and results are as follows:1.Effect of rigor mortis on the gel properties of surimi from bighead carpThe effects of post mortem pH and rigor mortis on the gel and rehoelogical proterties of surimi from bighead carp were investigated. Results indicated that post mortem changes concerning the solubility of surimi and changes of cathepathin can have a big influence on the gelation properties. Under the experitmental condition, post mortem pH decreased dramatically from7.26to6.51within10h, while rigor mortis increased from19h and reached the top at48h. Then, rigor mortis began to decrease, but pH started to go upward. By comparing the gel properties under different post mortem time, gel properties of Oh is superber than the top rigor mortis.2.Study on the factors concerning the gelation of surimi from bighead carpThe effects of pH, ionic strength, washing times, washing methods and heating methods on the gelation properties of bighead carp were investigated. Results indicated that all factors influence the gelation properties significantly. The optimal parameter is:0.1%NaCl washing methods, pH6.5, ionic strength0.6, two washing times. 3.Optimization of gel properties of surimi from bighead carp with response surfaceMuscle of bighead carp is used as the material to analyze the model of gelation processing of bighead carp. The effects of pH(Χ1), ionic strength(Χ2) and washing methods(X3) on gel strength(Y1) and water holding capacity(Y2) were studied. The equation is set according to the regression analysis: Y1=501.72-139.74Χ1-22.57Χ2+23.77Χ3-1.58Χ1Χ2-92.22Χ1Χ3-86.91Χ2Χ3-198.7Χ12-4.26Χ22+120.89Χ32Y2=93.85+2.75Χ1+0.98Χ2-0.98Χ3+2.Χ1Χ2+1.09Χ1Χ3+0.056Χ2Χ3-4.48Χ12-0.73Χ22+1.21Χ32The equation can vividly depict the connection of gel strength and water holding capacity and pH, ionic strength, washing methods, which can forecast and control the properties of surimi products.