Evaluation And Improvement Of Edible Quality Of Texturized Soy Protein Imitating Beef

High Moisture Texturized Vegetable Protein(HMTVP)shows the great potential to reach the consumers'expectations as a substitute of meat products,nutrient balance,and meat analogues.Recently,many researchers have explored similarities of functional characteristics,nutritional characteristics,and fiber structure of HMTVP to different meat products,in order to achieving similar sensory evaluation to the animal meat.However,there are few studies on the preparation of meat-like HMTVP through comparative analysis.In this study,we explored the characterization method of beef doneness classification,evaluated the quality characteristics of HMTVP based on the physical properties of cooked beef,and further optimized the extrusion process and formula.It is expected to provide a theoretical basis and technology for industrial production of HMTVP to produce imitating beef products.The main contents including three parts are presented as follow:(1)The relationship between the denaturation degree of muscle protein and the content of Free Amino Acid(FAA)in beef under different processing conditions was studied by chemical composition analysis method for the first time.The content changes of FAA in beef with different doneness were determined,and the discriminant function of beef doneness was established by using Fisher discriminant analysis method.The results of commercial cooked beef were compared to verify the practical significance of taking center temperature as the precondition of beef doneness.Based on the establishment of the doneness classification,the change rule of physical properties of beef was explored.The hardness,chewiness,maximum shear force,strain rate and modulus of elasticity were studied by testing the texture,creep and shear properties of beef with different doneness.The results showed that the content of total FAA in meat samples decreased by Logistic curve with the increase of doneness,and the contents of hydrophobic amino acids,sulfur-containing amino acids and aromatic amino acids in meat samples decreased regularly,and the enzymatic hydrolysis of muscle protein also decreased gradually.The results showed that the physical properties of beef increased with doneness in a power function,while the strain rate decreased in a power function.The maximum hardness and chewiness were 12.34 kg and 6.97 kg,respectively,and the minimum strain rate was 0.88×10^-4.The reference range of maximum shear force and elastic modulus is2.91 kg?6.61 kg and 5.37×10³?30.21×10³.(2)Taking the quality characteristics of different doneness beef as the reference index,the HMTVP quality of six kinds of formula was evaluated,and the technical index and reference range were determined.The quality of HMTVP was evaluated to obtain the reference range of raw materials for the preparation of imitating beef HMTVP.The results showed that the formula 6(Gluten:Soy Protein Isolate:Soy Meal:Starch=4:3:3:2)with the highest starch content(dry basis)has a hardness of 17.66 kg and chewiness of 15.48 kg,were the most close to the quality characteristics of Grade 5 cooked beef,and their elastic modulus was also similar to that of cooked beef(5.37×10³?30.21×10³).At the same time,the total sensory score of sample 6 was significantly higher than that of other formula products,and the color of sample6 was the brightest and whitest,and the hardness and chewiness taste index were higher.(3)Hardness(12.34 kg),chewiness(6.97 kg)and strain rate(0.88×10^-4)of cooked beef were selected as the reference indexes for the improvement of HMTVP,and the optimal formula 6 was optimized.The optimal proportion of each component in the raw material was obtained through response surface optimization test.On the basis of the optimal extrusion formula,the water rate and feeding rate of extrusion process were optimized.The results showed that:when soy protein isolate 32.79%,starch 15.83%,gluten 24.43%,soy meal42.78%,water rate 3.4 L/h,feeding rate 2.8 kg/h,the extruder hardness is 12.15 kg,chewiness is 8.27 kg,strain rate is 0.92×10^-4.At this time,the actual moisture content of the product is58.62%,and the physical parameters are within the range of cooked beef.In addition,imitating beef HMTVP as the main raw material of homemade beef and cooked beef taste similarity was70.67%,and its structure characteristics,the sensory index and commercial beef 1 difference was not significant.The product has high acceptability,solved by extrusion“the meat”as meat can't directly edible question.