Study On Improving The Gel-formation Property Of Tilapia(oreochromis Niloticus)mixed Surimi

As a high quality and high protein product,surimi products are popular with consumers both at home and abroad.With the overfishing and the environmental pollution,the production of traditional surimi processed raw materials has decreased obviously,and the demand for new type of raw materials is more and more urgent.Using tilapia and marine fish as raw materials to prepare mixed surimi products,not only the high value of tilapia can be realized,but also the variety of surimi products can be enriched.In this paper,tilapia is mainly used to prepare mixed surimi by adding marine fish and additives,and study the improvement of several kinds of marine fish and additives on the gelation characteristics of tilapia surimi.The main research contents and conclusions are as follows:(1)By researching the tilapia surimi,five kinds of sea surimi(sea bass,yellow croaker,golden pompano,red fish,mackerel)and kite cuttle surimi to compare the gel properties(gel strength,whiteness,salt soluble protein content,sulfydryl content)of them,we can find that the sea bass,mackerel surimi have better gel properties,as a result,they can be used as raw materials to prepare tilapia mixed surimi and develop the products with strong gelatin characteristics,good flavor and low cost.(2)Selecting tilapia respectively mixed with four marine fish(mackerel,sea bass,golden pompano,kite cuttle)to prepare mixed surimi in order to get the surimi products with good gel properties and lower cost.By measuring the gel properties of the tilapia mixed surimi,get the best mix proportion.The results showed that when tilapia surimi added separately with 60% mackerel,60% sea bass,40% golden pompano and 40% kite cuttle,compared with the single tilapia surimi,the gelatine strength of the tilapia mixed surimi were improved by the percentage of 82.5%,79.4%,44.3%,27.2% and the salt soluble protein content of the tilapia mixed surimi were improved by the percentage of115.6%,104.5%,100.4%,75.6%.And mixed surimi were mainly of tilapia,so choose 5%-25% sea bass adding amount to research the effect of mixed surimi.When adding 25% of sea bass,the gel strength,content of salt soluble protein,whiteness of mixed surimi were2585.10 g.mm,29.73 mg/mL,72.62%,comparing with the single tilapia surimi,that were improved by the percentage of 27.3%,63.8%,5.2%,but the sulfydryl content had no significant change.Therefore,the addition of 25% sea bass can greatly improve the gel properties of tilapia surimi,which laid a foundation for the development of the tilapia mixed surimi products.(3)The effects of additives on the gel strength and water loss rate of tilapia-sea bassmixed surimi were analyzed by using SDS-PAGE gel electrophoresis.By adding starch sugar?protein?natural extraction and salt compounds in the mixed surimi.It has showed that the gel strength of additive group mixed surimi had significantly increased than control group(p<0.05),especially the TGase enzymes and additives group mixed surimi.The gel strength of TGase with bovine serum albumin?tannic acid?citric acid sodium group mixed surimi respectively reached 4563.87 g·mm ? 4357.06 g·mm ? 4357.06 g·mm,compared with the control group that were respectively increased of 76.55% ? 68.55% ?47.35%;Filtration rates of mixed surimi were also significantly lower than 7.33% of control group(p<0.05)that respectively were 1.4%?1.62%?1.36%;The MHC?Actin and TM bands in electrophoresis were wider,indicating that the fibrin fibers of the mixed surimi had higher crosslinking degree and better gel properties.SDS-PAGE gel electrophoresis results showed that adding carrageenan,sodium ovalbumin,citric acid,tannic acid and bovine serum albumin made the myofibril protein autolysis obviously inhibited,myosin heavy chain(MHC),Actin(Actin and tropomyosin(TM)stripes obviously deepened,and add the TG enzyme band wider,shows that the myofibril protein crosslinking degree is higher and had better gel properties,TG enzyme combined with the additives can significantly improve the gel properties of mixed surimi.(4)By determinating the gel strength,moisture,whiteness,and sensory characteristics of tilapia surimi and several tilapia-sea bass mixed surimi,it was determined by correlation analysis that the gel strength,moisture and sensory characteristics were the main index to influence the quality of mixed surimi.Cluster analysis was used to divide the tilapia-sea bass mixed surimi into three levels(A,AA,AAA).The simple and effective evaluation methodology was established,which was convenient to distinguish and choose,satisfying the different tastes and needs of consumers,and provided a reference basis for the selection and evaluation of tilapia mixed surimi products.