1.Processing conditions of soybean textured protein.
The quality requirements of soybean textured protein products are: uniform surface color, no hardness, high elasticity, water absorption and oil absorption, and porous spongy shape. Through several years of production practice, we have realized that in order to produce tissue protein that meets the above requirements, there must be strict requirements from raw materials to processing. The main conditions are:
a. High-quality soybeans must be selected as raw materials, and the grade of soybeans must at least meet the national third-grade standard;
b. Before processing defatted edible soybean meal (white bean flakes), soybeans must be cleaned repeatedly to remove various impurities;
c. Remove the bean skin and watercress. There are impurities, bacteria, oxidase, etc. on the surface of the bean skin and watercress. At the same time, most of the bean skin is fibrous tissue, so it should be removed during the pretreatment process;
d. The control standard for soybean drying temperature is not to exceed the critical temperature of protein denaturation, and the general control temperature is not to exceed 70 degrees;
e. In the production process of edible white bean flakes, low temperature or flash desolventization process must be used to ensure that protein denaturation is kept to a minimum. The NSI of white bean chips should be greater than 70%;
f. The residual oil content of white bean chips should be controlled below 1%, otherwise it will affect the puffing effect;
g. Adopt advanced puffing equipment to ensure the shape and structure of the product.
2.Processing technology of soybean textured protein
The production process of soybean textured protein is roughly as follows: white bean flakes are ground into defatted protein powder by worm gear grinder. The defatted protein powder that meets the specifications is mixed with 25%-30% process water and enters the X-200 extruder. The feed rate of this extruder is 0.85-1.5 tons/hour, the speed of the extruder is 250 rpm, and the screw speed is 35-60 rpm. The temperature control is divided into four upper sections, the first section is 35-40°C, the second section is 115-120°C, the third section is 90-100°C, and the fourth section is 85-90°C. In this way, it is heated and extruded in the X-200 extruder to change the structural state of the protein. There is a mold at the end of the extruder to make the product into a certain shape. The tissue protein coming out of the extruder passes through the variable speed knife to cut the product -31- into the required shape and length of the product. After being dried and cooled, it is screened through a vibrating screen into the finished product warehouse and packed into bags.