Isolate Soy Protein as been widely accepted by most manufacturers in various combination methods, especially the chopping machine method is the most popular, the main reason is that it has many functions and the manufacturing process is relatively flexible. In terms of its application, compare the advantages and disadvantages of the following application methods.
- Rehydration method
Put soybean protein isolate and 4 to 5 times of ice water into the chopping machine and chop and mix at high speed for 1 to 2 minutes, then add lean meat, ice water, polyphosphate and salt, chop and mix at high speed for 2 minutes, To extract salt-soluble protein, the temperature is just controlled at 2-4°C, because this temperature is the most suitable temperature for extracting salt-soluble protein. After extracting salt-soluble protein, add fat fat and ice water and continue chopping 2min, at this time the temperature should be around 6-8°C, which is the most common method.
- Gel method
First, use 4 times of water to isolate the soybean protein, emulsify it at high speed with a chopping machine, and then add it to the chopping mix with lean meat according to the required amount. The other steps are the same as the above-mentioned rehydration method. In addition, the gel method can be stored in the refrigerator The warehouse is ready for use. Although the protein isolate can be stored in the refrigerator for 2-3 days, it is prone to rancidity and bacterial growth. It is recommended to use it up as soon as possible.
Small pieces of meat no larger than 6 cm can be added with soy protein isolate by rolling and kneading, while for some larger meat products, injection can be used, and the modified SPI is dissolved in brine, and then the solution is injected into the meat In the block, the pickling liquid can be evenly dispersed in the meat block, shortening the curing time and increasing the yield of the product.
- Emulsified oil method
Raw materials for producing emulsified oil from protein isolates can use chicken skin, fat, butter, soybean oil and pig skin as raw materials. The method of making emulsified oil is mainly to rehydrate the protein isolate with a chopping machine, then add oil, continue chopping and mixing to form emulsified oil, and then use it for later use. In the production process of emulsified products, emulsified oil is added after the salt-soluble meat protein is extracted, which is more complicated than the gel method. However, proper processing and addition of emulsified oil can not only reduce product cost, but also increase product aroma and flexibility.
- Dry addition
This method is simple to use. First, add protein isolate to lean meat, chop and mix for a while, add 4 times of water, chop and mix for 1-2 minutes, then add polyphosphate, ice water and salt, and continue chopping and mixing for 2 minutes. Same as above. However, there is also a method of directly adding dry matter such as protein isolate and starch to chopping and mixing. This method is convenient, but because the soybean protein isolate has not been fully rehydrated and its function has not been fully exerted, the product made under the same formula will be softer, and the water absorption and oil retention will be poor, so this method is not recommended. . Another example: add isolated soybean protein and lean meat together, but without rehydration, this effect can neither properly rehydrate soybean protein isolate, but also affect the extraction of salt-soluble protein, and the manufactured product will be softer. Therefore, the rehydration and addition steps also affect the quality of the final product.
Due to the influence of the properties of the protein isolate itself, a certain reversible reaction will occur when it encounters salt, which will weaken its emulsifying properties, oil retention, and water retention properties. Therefore, no matter what method is used to produce emulsified meat products, in order to maximize the functionality of soy protein isolate, soy protein isolate must be completely rehydrated.