Quality Of Tilapia Surimi Gel Improved By Mixing Extreneous Protein

With the rapid development of aquaculture of Tilapia, there prompted a need to the valueadded product for the local economy in response to the high tilapia production. Processingconditions were optimized for tilapia surimi gel added with different food ingredients andadditives. The resultant gel quality was investigated by texture analysis and sensory evaluationThe main results were as follows:(1) The optimized processing conditions for control gel were: wash once with ice water andthe water-surimi ratio was five to one; moisture content of surimi was82%before blending andNaCl concentration was2.5%; the mixture was blended for3min and heated from40°C/30minto90°C/20min.(2) Addition of non-muscle protein or starch affected the gel strength of tilapia surimi, withthe increase of non-muscle protein or starch content, the gel strength decreased significantlyfollowing a negative non-linear pattern. Salted egg white enhanced the whiteness of surimi gelsignificantly compare to wheat gluten and soy protein isolate. Gel strength was still acceptablewhen salted egg white added to the maximum amount.The gel quality and flavor of tilapia surimiwere satisfactory when the mass ratio of salted egg protein addition to total protein of mixturewas less than2/15.(3) With the increase of corn starch content, the breaking force and water retention propertyof surimi gel increased, but the deformation decreased significantly, without considering thewater content of total mixture. Gel springness and hardness were optimal and the waterrentention was improved when corn starch content was12%. Gel strength, gumminess,chewiness and springiness were improved when the ratio of κCG and KGM was2:1and theaddition level was0.1%. Gel quality was also improved when the addition of phosphatecompounds (the ratio of sodium tripolyphosphate, sodium pyrophosphate and sodiumhexametaphosphate was2:2:1) was0.1%.(4) The optimum addition levels of salted egg white, corn starch, κCG and KGMcompound(2:1, w/w), phosphate compound were determined by orthogonal test and the optimumaddition levels were15%,14%,0.05%and0.1%respectively. The gel properties and flavor ofthe mixture at the optimal conditions were satisfied compare to pure tilapia surimi.