Phosphates play a role in meat products in maintaining the water-holding capacity of meat and enhancing its binding force. During the processing of meat, such as freezing, refrigeration, thawing and heating, a certain amount of water is lost, causing the meat to become harder and losing some soluble proteins and other nutrients due to water loss.
When phosphates are added to meat, they can improve the water-holding capacity of the meat, allowing it to retain its moisture during processing, reducing the loss of nutrients and maintaining the tenderness of the meat.
At present, a total of 18 types of phosphates have been approved for use in China, including sodium tripolyphosphate, sodium hexametaphosphate, sodium pyrophosphate, trisodium phosphate, disodium hydrogen phosphate, monosodium dihydrogen phosphate, acid pyrophosphate, disodium dihydrogen pyrophosphate, etc.
Adding these substances to food helps diversify food varieties, improve their color, aroma, taste and appearance, maintain the freshness and quality of food, and meet the needs of processing techniques. They are very important quality improvers.
1. Application of phosphates in meat products
① The role of phosphates in meat product processing
1) Increase the pH value of meat; 2) Chelate metal ions in meat; 3) Increase the ionic strength of meat; 4) Dissociate myosin.
Therefore, adding phosphates can improve the water-holding capacity and yield of products. However, the ability of phosphates to improve the water-holding capacity of meat and improve the texture of meat products depends on the type of phosphate used, the conditions of the phosphate system, and the amount of phosphate added.
② The application of phosphates in improving the water-holding capacity of muscle protein gels
The order of factors affecting the water-holding capacity of chest muscle protein gels is: sodium pyrophosphate > sodium tripolyphosphate > sodium hexametaphosphate; the order of factors affecting the water-holding capacity of leg muscle protein gels is: sodium hexametaphosphate > sodium pyrophosphate > sodium tripolyphosphate.
The different effects on the two types of muscles are mainly due to the different types of muscles and the different mechanisms of action of phosphates. Experiments show that sodium pyrophosphate has a significant effect on the water-holding capacity of breast meat. The reason is that sodium pyrophosphate increases the pH value, improves the water-holding capacity of the gel through hydration, and at the same time dissociates myosin into myosin and actin, and the protein molecules bind water to improve the water-holding capacity.
Sodium tripolyphosphate has no obvious effect on the water-holding capacity of leg muscle protein gels. At this time, the structure of the gel affects the water-holding capacity. Good water-holding capacity of the gel indicates that the gel network is more delicate, and a large number of small holes are evenly distributed in the gel network. With the help of capillary force, some water is retained.
In terms of the thermal-induced gel strength of muscle proteins, phosphates have a reducing effect on the gel strength. Foreign literature reports that sodium pyrophosphate makes myosin unstable, reduces gel strength, and interacts with myofibrillar gel. Sodium tripolyphosphate also makes myosin unstable, and improves the gelation of myofibrillar protein when 0.3 mol/L and 0.4 mol/L sodium chloride is applied, but reduces the gelation ability at 0.6 mol/L sodium chloride.
Sodium hexametaphosphate has no effect on the denaturation of myosin, but it increases the gel strength. The effect of phosphates on muscle proteins is mainly attributed to the changes in ionic strength and pH value they bring.
③ The application of phosphates in improving water-holding capacity and yield
Adding phosphates to meat products can improve the texture of the products, increase the water-holding capacity and yield of the products, and improve the texture of meat products, thereby reducing the cost of the products without reducing the quality of the products.
The principle of phosphates improving the water-holding capacity of meat products is: sodium tripolyphosphate and sodium pyrophosphate can increase the ionic strength of the meat system by changing the potential of protein charges and deviating from the isoelectric point, causing the charges to repel each other, creating more space between proteins, that is, the "swelling" of proteins, allowing the meat tissue to hold more water and improve the water-holding capacity; sodium hexametaphosphate can chelate metal ions, reduce the binding of metal ions to water, and allow proteins to bind more water and improve the water-holding capacity. Practical experience has shown that the combined use of multiple phosphates is more effective than the use of a single phosphate, so compound phosphates are usually employed to enhance the effect. The optimal ratio of compound phosphates in most meat products (such as pork ham, beef, and surimi) is 2:2:1 (sodium tripolyphosphate: sodium pyrophosphate: sodium hexametaphosphate), but the optimal dosage varies greatly among different products. For ham, the optimal dosage is 0.4%, while for fish meat, it is 0.5%. Compound phosphates offer better water retention in surimi products compared to single phosphates, and the color, flavor, and texture of the products are also improved. However, in chicken products, the optimal phosphate ratio for achieving the highest yield is 32.6% sodium hexametaphosphate, 45.6% sodium tripolyphosphate, and 21.8% sodium pyrophosphate. The higher the addition of compound phosphates, the higher the yield, meaning the greater the positive effect on water retention of the products. However, when the dosage exceeds 0.4% for chicken and 0.5% for fish meat, the upward trend of product yield slows down.
④ Application in Improving Tenderness
The complex phosphate is alkaline and can increase the pH value of meat, promoting the tenderization of meat by calcium-activated enzymes. Meanwhile, the complex phosphate carries a large number of negative charges, and a relatively low concentration of complex phosphate can significantly increase the ionic strength of the solution, thus chelating metal ions such as magnesium and zinc, exposing the -COO- end of proteins, enhancing the electrostatic repulsion of meat, making the meat relax, and increasing the tenderness of meat.
Since the tenderness of meat is related to the content of connective tissue and myofibrils, the more cross-linking of collagen in connective tissue, the worse the tenderness of meat. After adding complex phosphate, the solubility of collagen can be increased, reducing the cross-linking of collagen in connective tissue and improving the tenderness of meat.
Complex phosphate can also dissociate actomyosin, relieve muscle rigidity, and improve the tenderness of meat. The ratio of complex phosphate is: tripolyphosphate: pyrophosphate: hexametaphosphate - 2:2:1, and the addition amount of 0.5% is the best for tenderizing beef and rabbit meat. The injection marination method for 16 hours is recommended.
3. Safety Issues of Phosphate
Phosphate is an essential component of human tissues such as teeth, bones, and enzymes, and plays an important and indispensable role in the metabolism of important nutrients such as carbohydrates, fats, and proteins. Therefore, phosphate is often used as a food nutrient fortifier.
However, when the phosphate content in the diet is too high, it can reduce the absorption of calcium and cause calcium loss in bone tissue. If this persists for a long time, it can lead to delayed development and bone deformities. Therefore, the addition and use of phosphate must be strictly within the range specified by the state.
3. Usage Methods of Complex Phosphate
There is a phosphate-decomposing enzyme in meat products that can decompose phosphate and render it ineffective. Therefore, in the meat product production process, special attention should be paid to choosing the appropriate process for addition to avoid destroying the effect of phosphate.
Generally, in meat product production and processing, the best effect is achieved when it is used during the mixing and blending after marination; there is also a method of solution marination. At the same time, it should be noted that excessive addition of phosphate can deteriorate the flavor and color of the product and is not conducive to human health.
Therefore, the dosage of complex phosphate for chicken is 0.4%, and for fish meat is 0.5%. The amount of phosphate added to meat products should be in accordance with the standards issued by the state.
Like other additives, quality improvers will surely be compounded into compound quality improvers according to certain formulas. Such quality improvers are very convenient and effective.
In the United States, carrageenan and phosphate additives have been successfully used to produce low-fat, low-salt, low-calorie, and high-protein poultry meat products with health benefits. These additives are mainly used to retain moisture in poultry meat and reduce the salt content in the product by 50% compared to the original. In addition, they have the characteristics of increasing the volume of cooked poultry meat products, maintaining product flavor, improving structure, and enhancing cutability. The phosphate-ascorbic acid compound quality improver can be used to inhibit the oxidation of meat fat.
Helper Machinery Group Co., Ltd.
