What are the applications of expansion technology in the development of protein ingredients?

Protein raw material puffing is at a certain temperature, pressure, moisture and time under the action of raw materials subjected to high temperature, pressure, mixing, shear, paste, ripening, sterilization, etc., high temperature and high pressure protein feed in the extrusion die hole instantaneous decompression, the material volume expansion, a large number of air, water molecules expand dramatically and enter the material, so as to make the formation of the material within the porous structure of the puffed structure, the volume increased a few times to a dozen times. In this process, protein feed materials in the structure of the components and physical and chemical properties of the changes, such as protein denaturation, starch pasty, fiber, anti-nutritional factors and other degradation of varying degrees, some of the enzymes and toxic substances are destroyed. Expansion of the main components of protein raw materials on the impact of
1. Protein
Protein feed materials in the protein content of 20% ~ 80%. Protein molecules in the high-energy field, its original three-dimensional structure is destroyed, the unfolding of the globular protein molecules re-arrangement of combinations, in the die hole shear and decompression, protein molecules into a line of spray, a large group of proteins split into smaller linear protein, so that the protein peptide chain inside and outside of the hydrogen bond, disulfide bonds and ionic bonds to rearrange the distribution of the organization of the denaturation and disulfide chain breaks, the process of cystine In this process, cystine is destroyed.

At higher barrel temperatures and lower feed moisture, the free terminal amino group of lysine reacts with other amino acids and may also react with free sugars, which will reduce the nutritional value. Therefore, in the puffing process, we must optimize the process parameters and methods, so that the product has a high digestibility, but also to reduce the destruction of amino acids.
2. When starch protein feed is puffed, the starch will undergo pasting reaction, and the starch will be degraded during the pasting, which improves the starch digestibility. The main feature of starch pasting is that the starch is mixed with excess water, the temperature rises under the action of shear extrusion, and the water penetration increases, and a large amount of water is absorbed, so that the starch granules are ruptured and pasted. Pasteurization is manifested in the change of hydrogen bonding in starch molecules, and the water holding capacity of pasted starch is significantly improved. Expansion makes the starch chain exposed, which can accelerate the enzymatic hydrolysis.
3. cellulose protein feedstuffs in the extrusion process, soluble dietary fiber (SDF) content increased, the total fiber content in the extrusion also reduced, increased soluble dietary fiber xylose, arabinose, mannose and glucuronic acid composition.
4. Vitamins protein feedstuffs in the extrusion expansion, vitamins will be damaged, different kinds of vitamins in the expansion of the stability of a great difference.
Among fat-soluble vitamins, VD and VK are quite stable, VA and VE and their compounds, carotenoids and tocopherol monomers are unstable under the action of oxygen and heat, and higher barrel temperatures (200 ℃) can reduce β-carotene by more than 50%. Oxidation promotes pigment loss, which can be reduced by adding antioxidants. Among water-soluble vitamins, VB is very sensitive to heat treatment.
Killeit (1994) test proved that when puffing VB, loss of 5% to 100%. Andersson and Hedlund (1990) also noted that during dry extrusion VB; loss was higher, while riboflavin (VB2) and niacin were unaffected; VC is also a raw material that is sensitive to heat and oxidation.
5.MineralsWhile minerals are necessary for animal health, little research has been done on their stability during extrusion-expansion processes, due to the conclusion that minerals are very stable during long-term non-extrusion processing.
Therefore, current research has focused on only two topics: first, the adhesion of fibers and other macromolecules to minerals; and second, the fact that wear of screws and jerricans can cause an increase in the mineral content of the product. It has also been reported that extrusion may reduce the utilization of some of the minerals absorbed in aquafeeds.
6. Other extruded puffing can significantly reduce the content of endogenous toxins and anti-nutritional factors in protein feeds. Soybean puffing will greatly reduce toxic ingredients and anti-nutritional factors, such as trypsin inhibiting factor, hemagglutinin, and sensitizing globulin.
Canola meal, cotton meal, castor seed meal, flaxseed meal, etc. After puffing, it will also significantly destroy the toxins and anti-nutritional factors. In addition, due to the combined effect of high temperature and high pressure, so that the vast majority of harmful microorganisms in the extrusion and expansion process is killed. Expansion technology in the development of protein raw materials in the application of 1. Soybean meal
Soybean embryo by extrusion of oil production process to extract oil products or soybean meal obtained after the expansion process known as expanded soybean meal.
Soybean meal puffed features: (1) improve pretreatment capacity. Soybean puffing pretreatment only need to be crushed and rolled into thick pieces, the first part of the oil extraction, and then extrusion can be leached.
(2) Improve the leach production capacity. After extruding and expanding the material is porous cylindrical particles, compared with the rolled embryo volume weight increased by 40% to 43%, in the leaching machine in the material layer height and leaching time remains unchanged, the leaching machine production capacity can be increased by more than 40%.
(3) Speed up the leaching rate. Expanded material with multiple microporous, and oil cell rupture, good aggregation, making the solvent penetration and percolation speed up, relatively reduce the leaching time, improve the efficiency of the leachers, reduce energy and steam consumption, reduce production costs.
2. flaxseed flax, also known as caraway, containing linolenic acid, linolenic gum, lignans, flax proteins and other nutrients and health components, with blood lipids and anticancer health and other efficacy, many countries will be flaxseed as a health food directly added to the food in small quantities.
Flaxseed contains some anti-nutritional factors, such as phytic acid, cyanogenic glycosides, antipyridoxine (VB,) factors, etc., the presence of cyanogenic glycosides and anti-VB factors limit the application of flaxseed in food and feed.
Song Chunfang et al. (2006) test proved that the extrusion puffing temperature at 147 ~ 153 ℃, flaxseed water content of 13.8% ~ 17.6%, the raw cyanogenic glycosides and the vast majority of the enzyme in flaxseed has been destroyed, the hydrocyanic acid production is very low, and due to the sudden release of puffing pressure in the evaporation of water at the same time, the hydrofrequency acid is also volatilized, analyzed, the probability of removing hydrocyanic acid in flaxseed is higher than 90% of the probability of 95%.
In addition, extrusion puffer is a set of transport, mixing, heating and pressurization and other units of operation in one continuous reactor, the material role of a short time, nutritional loss is small, for linseed detoxification treatment is more appropriate.
3. animal blood meal animal blood meal crude protein content of up to 80% or more, is a very good animal protein feed. But the general processing method of blood meal produced by animals after eating is difficult to digest, palatability and nutritional balance is poor. This is mainly due to the blood cells belong to the hard proteins, in the process, the blood cell membrane is not fully destroyed or hard proteins in the blood meal is not fully denatured, it is difficult to be digested and absorbed in the animal body.
Therefore, the key to processing blood meal is to destroy its original molecular structure with the help of external forces during processing, so that the blood cells rupture, the nutrients in the blood cells are completely released, extrusion and puffing processing technology can realize this requirement.
After extruding and expanding the blood powder after microscopic examination, there is no intact blood cells, its product quality and digestibility is better than fermented blood powder and spray-dried blood powder. Expansion processing makes protein denaturation, which makes it easier for protease to enter into the internal, expanding the protein digestive enzymes and protein contact area, so that it is easier to be digested and absorbed by animals.

4. Livestock and poultry waste livestock and poultry waste (such as poultry carcasses, scraps, offal, manure, etc.) has the potential value of utilization, which contains a large number of nutrients. However, the direct use of these livestock and poultry waste has certain dangers and limitations, they contain mold and harmful substances, and digestibility and low utilization value, the application of extrusion technology can partially solve these problems, not only to eliminate the pollution of livestock and poultry waste on the environment, but also to expand the feed resources, turning waste into treasure. Some countries in the European Union will be eliminated after the crushing of poultry and soybean meal mixed with antioxidants, expanded into animal protein powder feeding.

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