The Effect Of Peanut Protein Isolate And Its Enzymatic Hydrolysate On Properties Of Myofibril Protein

Chicken has always been the preferred healthy food for consumers with the characteristics of "low fat,low cholesterol,low price and high nutrition".However,there has been a problem that the taste and flavor are not prominent and the nutrition is easy to be lost during processing.With the transformation of processing technology and consumption structure,the combination of plant protein and meat protein is a research hotspot.The addition of plant protein can make up for the nutritional loss in the processing process.China's peanut resources are rich and have high nutritional value,which is conducive to human absorption,but it is not fully utilized.In this paper,the effects of Peanut Protein Isolate(PPI)and its Peanut Isolate Proteolysis(PIP)on the rheological properties and gel properties of myofibrillar protein(Myofibrillar Protein)of chicken were studied,and applied to the processing of meat products,and the application of peanut protein isolate in meat products was widened.The optimal enzymatic hydrolysis process of PPI was determined by response surface analysis,and then PPI,the prepared PPI hydrolysate and their mixture were added to MP in different proportions to study their effects on the structure,functional properties and of MP.On this basis,the effects of the addition of phosphate salt on the coincidence system were investigated.Finally,peanut protein and its hydrolysate in appropriate proportion were added to fresh minced meat to prepare sausage and study their effects on the quality of sausage.The specific research results are as follows:1?The relationship between pH,temperature,enzyme addition and the degree of hydrolysis of peanut protein isolate was established by response surface analysis the optimized process parameters were as follows: enzyme addition 3.9%,enzymatic hydrolysis temperature 61 ? and enzymatic hydrolysis pH 8.5.The degree of hydrolysis and free radical scavenging rate of peanut protein isolate reached 41.53% and 86.64% respectively.The cell morphology of peanut protein isolate was observed by scanning electron microscope.The hydrolysate was dispersed,the surface was rough,and the morphology changed from ball to sheet.The molecular weight of hydrolysate obtained by ultrafiltration centrifugation was fraction I(>=3kda),accounting for 73.25%;The cell morphology of peanut protein isolate changed,the cells of enzymatic hydrolysate were dispersed and the surface was rough,and the morphology changed from spherical to flake.Fraction II Accounting for 26.62%(<3kda);Grade III accounted for 20.62% [1k Da,3kda);grade IV(< 1 k Da)accounted for6.13%,and the water holding capacity and oil absorption were greatly improved.2? The addition of PPI or its hydrolysates can affect the functional properties of MP.Where add PPI and its hydrolysates gradually reduce the carbonyl content of MP,slow down the oxidation degree of protein,change the lattice structure content in the secondary structure,increase the hydrophobic groups,enhance the hydrophobic interaction,and protect the tertiary structure of MP.Rheological tests showed that MP,MP-PPI,MP-PIP and MP-PPIPIP had obvious shear thinning phenomenon.With the addition of PPI and its hydrolysates,the apparent viscosity increased.In the temperature rise test,MP mainly has elastic deformation.Among them,the storage modulus G 'of MP-PPI-PIP system is the best,which is always much greater than the loss modulus G' '.At 20 ?,MP is in colloidal state,and G'is always greater than that of MP with the increase of PPI and its hydrolysates.The addition of PPI,PIP and PPI-PIP can improve the texture properties of MP emulsified gels,enhance the gel strength of MP,improve the water holding capacity of gels,and the effect of PPI-PIP is most obvious.After adding,the gel structure with good hardness,high elasticity and good water holding capacity can be formed.3.Through the changes of rheological properties of myofibrillar protein and gel properties,it is judged that phosphate has synergistic effect with PPI and its hydrolysates.It is found that the addition of phosphate will not affect the functional improvement of PPI and its hydrolysates on MP,but can jointly enhance the G',gel strength and gel texture of MP,and increase the whiteness of gel.4.Sausage was prepared by adding peanut protein isolate and its enzymatic hydrolysate with chicken breast meat,pig lean meat and pig Wuhua as raw materials.Electronic nose,color difference meter,calorimeter and texture analysis methods were used for research,it is found that peanut protein isolate and its enzymatic hydrolysate will not significantly change the nutritional composition,texture,smell and color of sausage,reduce the energy and fat content of sausage,maintain the color of sausage more stably,and will not affect the flavor of meat.There was no significant difference in sensory evaluation of sausages added with PPI and its hydrolysates,and there was no significant change in taste and color when stored at 4 ? for 7 days.