Application of soy protein in nine food industries

Soybeans, because they are rich in protein, are widely used as nutritious foods to supplement amino acids in the body. The protein content of soybeans is measured by an automatic Kjeldahl nitrogen analyzer. Compared with other ordinary foods, the protein content is more than ten times that of ordinary foods. Because of these elements, soybeans are widely used in some food industries. Let’s take a look at the applications of soybean protein in pasta products, aquatic products, meat products, soybean cheese, yogurt foods, fast food, breakfast cereals, and beer. And nine aspects of foaming agent. 

1. Utilization in noodle products: adding defatted soy protein to noodle products can improve the quality of protein in flour and increase the utilization rate of protein. Soy protein also contains reducing sugar, which can make the surface golden yellow during baking. In addition, because soy protein has high water absorption (2.5 times to 3 times), and is not easy to age and denature, the general addition amount is 3% to 5%. (1) Adding 2% to 5% of soy protein powder to the bread will increase the water absorption of the dough, improve the stretchability, and increase the mechanical adaptability. The processed bread has good color and luster, and is softer than ordinary bread processed with defatted soybean flour, and has a longer storage time. This is because the defatted soybeans have taken away the water in the starch, thus playing a role in preventing aging. In addition, as a yeast nutrient, defatted soy flour helps the dough to ferment and improve the quality of bread. Adding soy flour can also enhance nutrition, especially fortifying alanine. (2) When noodles are processed by adding soy protein powder to noodles, the dough has good water absorption, less strips after cooking, and longer cooking time. Due to the large water absorption, the yield can be improved, but the hardness of the noodles is not reduced. The taste is similar to strong vermicelli noodles. Adding 5%~10% soy protein powder to noodles and macaroni, the processed noodles have a smooth surface and strong gluten. However, if you add too much, the noodles are easy to cook and break, and the beany taste is also very strong. (3) Biscuits Adding 15% to 30% soy protein powder to the flour for the production of biscuits can greatly increase the protein content, increase the toughness and crispness of the biscuits, and also have the effect of preserving freshness. (4) Doughnuts defatted soybeans can prevent oil penetration when used for doughnuts and save fuel. At the same time, when defatted soybean flour is added to the doughnut mixture, on the one hand, the water absorption of the mixed noodle can be adjusted, and on the other hand, the flavor and color can be improved. The amount of water added for defatted soybeans should be 2% to 5% of the flour quality.

2. Utilization in aquatic products: Isolate soybean protein or concentrated soybean protein is generally used in aquatic product processing. It is more economical to use soybean protein powder to process aquatic products, and it can make full use of the functional characteristics of soybean protein. Adding 3%~10% of soy protein powder with fish quality to process fish sausages and fried fish rolls can increase the amount of water added and increase the elasticity and flavor of the product.

3. Utilization in meat products: (1) Minced meat products At present, the main purpose of adding soy protein to meat products is to utilize the functional characteristics of soy protein. In addition, adding soy protein to meat products can reduce the ratio of animal fat to animal protein, which is very beneficial for reducing cholesterol content. Soy flour, soy grits, soy protein concentrate, and soy protein isolate can be used as raw materials for minced meat products and added to meat products such as beef sausage, red sausage, meat bread, meatballs, patties, hamburgers, and luncheon meat. (2) Meat-like foods are also called structured protein products, and their chew and flavor are similar to meat. There are three main processing methods for this product: one is to use protein isolate to process spun protein to make it have the shape and flavor of meat; the other is to extrude the blended soybean meal and add flavor to make it chewy ; The third is to heat the separated protein to gel. It is to immerse the coarse fraction of the isoelectrically precipitated protein with water containing calcium hydroxide and sodium orthophosphate, and adjust the pH value from 4.5 to 5.5~7.5 to make it chewy . (3) Fibrous meat-like products Fibrous meat-like products are processed soy protein into beef, chicken, pork, ham, bacon and fish-like products. The fibrous protein is prepared by spinning, and then additives such as flavor, pigment and binder are added. Generally, fibrous meat-like products contain 40% protein fiber, 10% binder, 20% fat, 30% pigment, flavor and nutritional supplements. The tissue of fibrous meat-like products is softer than that of natural meat products, and can be refrigerated, frozen, or dried. (4) Extrusion-type meat-like products. Soy protein is continuously extruded under high temperature and high pressure to be processed into meaty soy protein food. After dehydration treatment, it will have the chewy and mouthfeel of meat. The biggest advantage of extruded meat-like products is that low-priced soy flour is used as raw material, and the higher-priced protein isolate is not used. After the soybean meal, fat, flavor, carbohydrate, pigment and other additives are blended and matured, they are extruded under certain conditions of moisture, temperature, time, and pressure. The composition of the product after extrusion is the same as that of defatted soybean flour. By adding fat, carbohydrates and other food bulking agents, the composition of the product can be changed. The full-fat soybean meal can also be used to process extruded meat-like products. (5) Heating gelatinized meat-like products Heating gelatinized meat-like products is a chewy gelatinous protein product, which is formed by adjusting the protein, moisture content and pH Chewy gel.

4. Utilization in soybean cheese: soybean cheese is a cheese food made from soybean milk through microbial fermentation. The microorganism used is Streptococcus thermophilus. Add 200mg of frozen Streptococcus thermophilus to 200g of sterilized soymilk. The bacteria must be cultured at 32℃ for 15h before they can be used. Add another 200g per 1mL of bacteria. Sterilize soy milk. Sterilization and cultivation of soy milk can be coagulated into cheese by the following three methods: one is adding calcium sulfate for calcium coagulation; the other is acid coagulation by adjusting the pH value to 4.5 with acetic acid; the third is lactic acid fermentation at 41°C. The three methods have differences in the yield of precipitated protein, water content and firmness. The yield of acid-coagulated protein is 67.8%, calcium-coagulated 54.1%, and lactic acid fermentation is 55%. Due to the good quality of lactic acid-fermented cheese, rennet and fat milk can be added.

5. Utilization in yogurt food: Bacteria sub(Lactobacillus) and Lactobacillus thermophilus were planted in 10% skimmed milk, cultured at 37°C for 18h, and then mixed and fermented. Add some amino acids to remove the peculiar beany smell of soybeans.

6. Utilization in fast food: adding 15% soybean flour or other soybean products to the puffed fast food raw materials can make the dough soft, easy to process, and can improve the bread crust and prolong the storage time. In addition, the addition of 10% to 15% soybean meal can improve the nutritional value of fast foods with starch as the main component, improve the balance of gluten protein and amino acids, and increase the protein content.

7. Utilization in breakfast cereals: Soy flour and concentrated soy protein can replace part of breakfast cereals. After mixing grains and soy protein, seasonings, pigments, vitamins and mineral additives are added to make breakfast cereals. While improving the nutritional value, the appearance and flavor of the product are improved.

8. Utilization in beer: As early as the 1930s, soybean flakes and soybean grits were used as beer fermentation media. At first, high-temperature soybean meal is used to extract oil, and then low-temperature soybean meal is used to extract oil by solvent leaching. Low-temperature soybean meal has high nitrogen solubility and is better for beer fermentation. As a yeast nutrient, soybean meal can provide amino acids, peptides, inorganic substances and vitamins, and is usually used in the form of ground liquid. In addition, adding hydrolyzed protein directly to beer can enhance the stability of beer foam and improve the flavor and quality of beer.

9. Use as a foaming agent: soy protein isolate can form stable bubbles after being washed with 80% to 90% ethanol; unheated defatted soybeans, the water extract when the pH is 4.5, which is usually called whey The part can form stable bubbles. The water-extracted part accounts for about 30% of the soybean meal, and the dehulled beans contain about 11% of total nitrogen and soluble sugar. The foaming power of this ingredient is roughly the same as that of ovalbumin. Enzymatic decomposition of soy protein can be used alone as a foaming agent. Generally, it is used in conjunction with ovalbumin or whole eggs as an improver of foaming speed, volume and stability. Compared with ovalbumin, soy albumin has a slower foaming speed and larger volume, and the foaming volume will not decrease for a long time. This foaming agent can be used in the processing of candies and desserts, such as processing marzipan, cream, candies and cakes.