Studies On The Processing Technology Of Tilapia Surimi And Composed Surimi

In this paper, tilapia is an important raw material and use low value marine fish (sardines) as additive.Study the rinse method and the type of heating of the tilapia surimi, the recruitment of low value fish surimi in tilapia surimi and the type of heating of the compound surimi. The main results and conclusions were as follows:The soluble protein of tilapia which was washed by water, salt washing, alkali washing was analyzed. The water-soluble proteins and salt-soluble proteins has significant difference in the content(p<0.05), the loss rate of water-soluble proteins were:56%、45%、48%, the loss rate of salt-soluble proteins were43%、26%、22%. Combining texture analysis and color analysis with sensory evaluation, the changes of texture, the gel-forming characteristics and color of the tilapia surimi were researched during processing; and I got the result:in gel strength, water (2043g·mm)> salt wash (1674.15g-mm)> blank (1173.67g-mm)> alkaline wash (694.11g-mm); comparison results of whiteness:alkaline wash(87.34)>(91.97)>salt water(87.30)>blank(84.60); Sensory evaluation results:water (grade A)=salt wash (grade A)>alkaline wash (grade B)>blank(grade B);the Tesults showed that the effects of tilapia surimi respectively washed by water and salt washing was better than the tilapia surimi washed by alkali washing. Washing method was analyzed as the single factor and orthogonal experiment. I got the result of surimi washed by the best method:the gel strength was5351.47g-mm, proved to be better than others.Finally determined the best washing method was washing with2times,0.25%salt water1times, washing4min each.The heating time and heating temperature were analyzed respectively as the single factor, gel degradation occur within the temperature range in55℃-70℃when we heated the tilapia surimi, and its gelling temperature range between40℃to45℃, the gelling time ranged between2.5h to3h. Used orthogonal experiment to analyse the type of heating, and finally determined the type of heating was41℃heating2.7h,83℃heating15min. Different added amount of sardine surimi in tilapia surimi had different affect on the changes of texture, gel-forming characteristics and color of tilapia surimi. The springiness, cohesiveness and resilience of composed surimi improved significantly the addition of sardine surimi reached10%.The whiteness reached91.59when the addition of sardine surimi reached30%,but its gel-forming characteristics only was4526.46g-mm, which was less than5895.90g-mm whose addition was10%. Finally determined the addition of sardine surimi was10%.The heating time and heating temperature were analyzed respectively as the single factor, gel degradation occur within the temperature range in55℃to75℃when we heated the composed surimi, and its gelling temperature range between35℃to40℃.At the same time, determined the gelling temperature was35℃, gelling time was4h when the addition of sardine surimi reached10%. Combining orthogonal experiment determined the type of heating was35℃heating3.5h,89℃heating25min.