| Shrimp clams are widely distributed,fresh and tender,and are a highly nutritious seafood product.The production in the Bohai Bay is particularly rich,but it is characterized by strong seasonality and difficulty in keeping fresh.As a salt-soluble protein structure group,myofibrillar protein in shrimp meat has a great influence on the water retention,texture and emulsification of meat products.Improving the functional properties of foods through exogenous additives is a hot topic of current research.Protein phosphorylation has been shown to be a very reliable means of improving the functional properties of proteins.Proteins in foods are more stable after phosphorylation and are more conducive to deep processing of foods.Inulin is a kind of soluble dietary fiber with high nutritional value.As a nutritional supplement,it is widely used in the food industry and has high commercial value.Trehalose is a non-reducing natural sugar composed of 1,1-glycosidic bonds,which has a strong protective effect and has been very effective as a magical cryoprotectant in seafood products.Therefore,this topic uses two kinds of sugars,inulin and trehalose,as exogenous additives.Firstly,the effects of different addition amounts of these two kinds of sugars on the characteristics of phosphorylated myofibrillar protein of shrimp and cockroach were studied.The sugars were compounded to study the effects of different compounding ratios on the properties of phosphorylated myofibrillar proteins.Based on this theory,the effects of the quality of these two types of prawn meatballs were studied.Finally,the kinetics of the storage quality of shrimp meat pellets was studied and the shelf life was predicted.The main findings are:(1)Phosphorus fibrinogen was used as a raw material to phosphorylate it,and different concentrations(0%,0.2%,0.4%,0.6%,0.8%,1.0%)of inulin and algae were separately added thereto.Sugar,examine the effects of emulsification,physicochemical and gel properties on phosphorylated myofibrillar proteins.The main indicators include:emulsifying activity and emulsion stability,surface hydrophobicity,turbidity,foaming and foam stability,gelatinity.Structure,gel water retention,gel whiteness and thermal stability.The results showed that when the concentration of inulin was 0.6%-0.8%,the turbidity,foaming and foam stability,elasticity and hardness of the pupae phosphorylated MP were significantly improved(p<0.05).When the concentration of trehalose is 0.4%-0.6%,the emulsification activity,turbidity,surface hydrophobicity,foaming(FC)and foam stability(FS),gel water retention,whiteness and coagulation of phosphorylated MP of Shrimp.The gelatinous structure has a significant improvement effect(p<0.05).The DSC curve reflects the proper amount of inulin and trehalose to facilitate the stability of the MP structure.(2)Inulin and trehalose in different proportions(0.6%trehalose + concentration 0%,0.2%,0.4%,0.6%,0.8%,1.0%inulin;0.6%inulin + trehalose with concentrations of 0%,0.2%,0.4%,0.6%,0.8%and 1.0%,respectively),added to the phosphorylated myofibrillar protein solution,and the results showed that the inulin and trehalose had obvious synergistic effects.(p<0.05),the appropriate ratio of inulin and trehalose compound can significantly improve the emulsification,physicochemical and gel properties of phosphorylated MP(p<0.05),and increase the proportion of trehalose to improve the effect(p<0.01),the addition of inulin and trehalose will make the groups in the myofibrillar protein solution better,and the spatial network structure of the gel will be more tightly bound.When 0.6%inulin and 0.8%trehalose were compounded,the emulsifying properties,gel elasticity and whiteness of myofibrillar protein were significantly improved(p<0.01).When 0.6%inulin and 0.6%trehalose were compounded,the turbidity,surface hydrophobicity,foaming and foam stability,gel hardness and water retention of phosphorylated MP were better(p<0.05).(3)Using inulin,trehalose and corn starch as experimental factors,the optimal addition range of these three additives was obtained by single factor experiment,and then inulin,trehalose and corn were optimized by response surface analysis.The best formula for the effects of three additives of starch on the quality of shrimp meatballs was 2.667%inulin,1.819%in trehalose and 19.303%in corn starch.Under this condition,the chewing degree of the shrimp meatballs was 1737.63±19.54,and the loss rate of the pressed juice was(10.17±0.94)%.The final result indicates that the addition of inulin and trehalose can effectively improve the quality of shrimp meatballs and promote the industrial development of shrimp and clam products.(4)The cooked shrimp and meatballs were stored at 4 ℃,10 ℃,and 20 ℃ for 7 days,and samples were taken once a day.The detection indicators were:texture(hardness,elasticity,chewiness),color difference(L*,a*,b*),total number of colonies,and sensory evaluation.To explore the key factors of quality change during the storage of prawn meatballs under different temperature conditions.The results showed that the storage effect was the best at 4 ℃.Pearson’s correlation analysis showed that the correlation between sensory scores and the total number of colonies was extremely significant(p<0.01).Therefore,the total number of colonies was used as the key factor,and the national standard end point value of 4.47 lg(CFU/g)was used as the shelf.The end point value of the period,the activation energy Ea of the total number of colonies was 59.8633 kJ/mol,the pre-exponential factor k0 was 7.27×109,and the Arrhenius equation of the quality change of the shrimp pill was obtained:k=7.27 × 10~9 exp(-59863/RT)After verification experiments,the relative error between the predicted value and the measured value is controlled within 10%.It can be proved that the kinetic model of the quality change of the cooked shrimp and meatballs established above is not only accurate,but also has practical value. |
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