The Study On The Effect Of Processing Techniques On The Trachinotus Ovatus Surimi Gel Properties And Surimi Protein Denaturation During Frozen

Trachinotus ovatus was bred largely in recent years in China, which was delicious,nutritious and abundant, so trachinotus ovatus was a good material for deep processing of surimi and surimi products. This article firstly analyzed the basic composition of trachinotus ovatus, then optimized the key factors of processing technology for the production of surimi gel by response surface method, and obtained the optimal process conditions. Secondly, studying the influence of adding trehalose, xylitol, compound phosphate on the gel strength, whiteness and water binding capacity of frozen surimi based on the optimum process conditions. And further studied the effect of adding these three cryoprotectants on salt soluble protein, Ca2+-ATPase activity, thiol, surface hydrophobic group, disulfide bond and p H. Finally, studying the influence of adding whey protein, Ca Cl2 and modified starch on surimi gel properties. All of the following conclusions:(1)Through analyzing the basic composition of trachinotus ovatus, found that the fish contained moisture was 70.51%, the total ash content was 1.37%, the crude protein was17.85%, the crude fat was 10.18%, and the p H was 7.1 after died, so trachinotus ovatus was a good material for processing of surimi and surimi products.(2)By screening tests found that the rinsing time, the rinsing times, the grinding time and heating time have significant effects on the gel strength, whiteness, and water holding capacity of trachinotus ovatus(P<0.05). Considering the influence of various factors on surimi gel properties and processing cost, it is concluded that the most suitable processing technology conditions of trachinotus ovatus surimi gel was that rinse time was 3 min, rinse 5 times, grinding time was 20 min, the first heating was 10 min, the second heating was 10 min.(3)Through single factor experiment found that alone added trehalose, xylitol, compound phosphate have different influence on surimi gel strength, whiteness and water holding capacity, but did not achieve the most ideal effect. Therefore, through response surface optimized obtain common effect of three kinds of cryoprotectants, and considered the actual needs. It is concluded that the optimal ratio of cryoprotectants added as follows:trehalose was 4.5%, xylitol was 6.7%, compound phosphates was 1.2%.(4)In the process of frozen, trachinotus ovatus surimi protein would have a series of change, leading to p H, salt soluble protein, Ca2+-ATPase activity, thiol, and gel strength decrease; leading to disulfide bond and surface hydrophobic group increase. These factors were not independent existence, but had certain correlation between each other,namely, the protein oxidative rancidity, led to p H decrease, the endogenous protease activity was reduced, the space of the protein molecule conformation changed, the molecular internal thiol and surface hydrophobic was exposed, oxidized to disulfide bond,the sal soluble proteint was reduced, and gel strength, which rely on the salt soluble protein to maintain three-dimensional network structure, was decrease.(5)Through single factor experiment can be found that alone added whey protein, Ca Cl2 and modified starch could improve the surimi gel strength and hold water, but reduced the whiteness of surimi gel. Comprehensive considerate the synergistic reaction of whey protein, Ca Cl2 and modified starch and the real demand, obtained the optimal ratio of elastic enhancer: whey protein was 10.22%, Ca Cl2 was 0.83% and modified starch was10.69%.