In recent years, nutritionists have paid great attention to the study of human protein intake, and noticed that there is a significant gap between protein intake in developed and underdeveloped countries. Over the years, it has been researched and screened by food scientists in various countries, and it is agreed that soybean and its deep processed products are the best source of plant protein.
However, soybeans contain a special smell, the soy flavor, and the undischarged soy flour is incorporated into soy milk or other foods, which will affect the original flavor of the food. For example, soybean is processed into a new type of deodorized soy flour, which is directly used as a soy milk to drink or blend into other foods, and has a rich bean flavor and nutritional value. Our company introduces foreign advanced technology and develops successful microwave soybean powder processing equipment. The physical and chemical indicators of the quality of the deodorized soybean powder produced by this equipment are in full compliance with national standards. Among them, the health indicators are much better than the national standards, E. coli ≤ 30 / 100 grams, the total number of bacteria ≤ 2000 / gram. The following is a comparison of the quality of the soy flour produced by the two processes and the equipment of the process.
First, the traditional soybean powder production process
The process involves soaking the soybeans first to swell the soybeans, facilitating the grinding and extraction of proteins from the soybean tissue. Soaked soy beans are ground, pay attention to the effect of soaking soybean water temperature, water quality and water consumption on soy protein. After the bean paste is reached, the soy milk is extracted. In order to fully extract the soy protein in the bean paste, the amount of water added to the water and the temperature of the water should be mastered. The soymilk extracted from the bean paste is concentrated, and dehydrated and dried under vacuum to prepare soy flour. The bacterial content requirements: Escherichia coli ≤ 30 / 100 grams, the total number of bacteria ≤ 19,000 / gram, the pathogenic bacteria is zero. The disadvantages of using the process to produce soy flour are long production cycle, large equipment investment, low soybean utilization rate, high energy consumption, high labor intensity and high product cost. On the other hand, due to the low-temperature drying method, the soybean meal cannot be effectively removed. taste. The whole soybean flour production process is as follows:
Soybean → soak → refining → filtration → concentration → vacuum drying (spray drying) → packaging → finished product
Figure 1 One of the soybean flour production processes
Second, dry process microwave soybean deodorization production process
At present, the research suggests that the mechanism of soybean meal is caused by the catalysis of broken soybeans in the air and the oxidation of polyunsaturated fatty acids into fatty acid hydroperoxides. Therefore, the activity of passivating lipoxygenase before breaking is the key to dislocation, and heating can make it lose the ability to catalyze the oxidation of unsaturated fatty acids. However, if the heating time is too long, the solubility is poor and the soybean utilization rate is low.
The new soybean powder (de-scented soy flour) is produced by microwave technology to dry and de-soy the soybean, and the traditional wet-process production process is changed to the dry production process, that is, the soybean is directly detached and ground without blisters. Shorten the whole soybean powder production process (Figure 2), and further improve the quality of soybean powder.
Soybean→Sorting→Microwave Dislocation (Sterilization)→Crushing (Peeling)→Packaging→Finished Products
Figure 2 production process of full fat soybean powder
The process sorts the soybeans by the sorter, and then sends them to the microwave heater by the conveyor belt, and is subjected to microwave irradiation for several minutes to perform deodorization and sterilization treatment. Microwave penetration heating is not affected by factors such as particle size and heat transfer. It is superior to conventional heat conduction, radiation and convection heating methods. In addition, the process flow shown in Figure 3 is also used in many years. Its products contain low fat and are excellent raw materials for the production of various low-fat foods.
Soybean → sorting → crushing → oil pressing → microwave processing → crushing → additive → mixing → packaging → finished product
Figure 3: Production process of defatted soybean powder
The dry-processed soybean powder process using microwave treatment has the characteristics of short production cycle, low equipment investment, high soybean utilization rate, good dislocation effect, low energy consumption, high automation degree and low production cost.
Third, the conclusion
1) Comparison of nutrients (protein)
The original process - the amount of soy protein dissolved by water, using nitrogen as a calculation method, the highest soluble 80 ~ 90%.
The new process - because it is not soaked in water, the whole soybean is directly dislocated and then ground into powder, except for the soybean skin, all proteins are retained.
2) Comparison of nutrient loss after heating (protein), effect of heat treatment of soybean meal on water solubility* (water-soluble nitrogen as a percentage of total nitrogen)
Processing condition temperature (°C) time (minutes) water
No treatment - 75.6
Microwave dry type 100664.4
High pressure heating 121607.5
High pressure heating 121108.8
High pressure heating 121549.6
Cooked 1006015.2
Note: * Water solubility is the amount of soy protein dissolved in aqueous solution, calculated as nitrogen.
It can be seen from the above table that the solubility of protein is related to the heating temperature and time, and also has a great influence on the presence or absence of water vapor, especially the solubility of steam heating is significantly reduced. In addition, the dry heating method shown in the table has less nutrient loss, and when heated by microwave, it is a kind of dry heat method, and the temperature required for heating is about 100 ° C, and the heating time is within several minutes. Can play the role of dislocation and sterilization. Water solubility exceeds 64.4%.
3) Economic benefits
1 production cycle calculation: the original process of soaking beans for a long time, conventionally immersed in 15 ~ 20 ° C water temperature for 10 to 15 hours. The whole process of soy flour production takes dozens of hours. The current process directly removes the soybeans by microwave heating, and the whole process of the soybean powder production takes about 20 minutes.
2 Soybean utilization rate: The original process relies on water to dissolve the protein of soybean, which is dried by refining and then dried, and can only use 40 to 60% of soybean. The current process directly heats and dehydrates 10% of the soybeans, and grinds them into powder form. All of them are used except for soybean hulls, and the utilization rate reaches 100%.
3 Equipment investment: The original process requires steam. Only the purchase of boilers and installation costs will cost several hundred thousand yuan. If it includes concentration equipment, vacuum drying equipment, soaking soybean equipment, etc., the whole process equipment is nearly one million yuan. The current process equipment investment is about 60-700,000 yuan.
4 Energy consumption: The original process requires coal, electricity and water. The current process requires only a small amount of equipment to cool the water. Since the microwave heating material directly applies energy to the material, the microwave energy is absorbed by the material itself, and no conductive medium is needed, which greatly saves energy.
Fourth, Jie full microwave equipment introduction
The microwave soybean dislocation equipment uses 2450MHz frequency, 20kW microwave power, tunnel form, and the equipment consists of microwave cavity, microwave energy suppressor, transmission mechanism, automatic control and detection system. The microwave system adopts the advanced foreign microwave energy feeding technology in the 21st century, which can quickly heat up the material and make the soybean evenly heated inside and outside, thus ensuring that the soybean is completely dislocated in a short time and the nutrient loss is kept at least. Multiple radiation in the microwave cavity acts simultaneously from the top of the material and under the material to ensure the uniformity of the material in the thickness direction. In addition to the soybean powder treatment, the equipment can also be used in one machine for drying, sterilizing and preserving other agricultural and sideline products.
The degummed bean powder produced by the microwave deodorization equipment can be directly used for brewing, and can be incorporated into other foods as a basic raw material to change the flavor of the food, for example, using bread flour to make bread, and preventing starch aging. And increase nutrition, improve flavor; when making instant noodles, blending certain soy flour can prevent oil penetration and save oil consumption of fried instant noodles; wheat flour and water kneading can produce gluten and elasticity, making bread is to use this property At this time, if the soy flour is kneaded in the flour in advance, in order to produce the same viscoelastic property, it is necessary to add a large amount of water, indicating that the soybean powder has a large water retention property; adding soybean powder to the sausage can make the fat Can be gathered together to improve the taste of the sausage; when making chocolate candy, adding soy flour can reduce the sweetness, and the chocolate will not soften and bite in the summer.