1. Factors affecting the tenderness of beef
1. The effect of age on tenderness
Beef varies greatly between cattle of different ages. Generally speaking, young beef is tenderer than old beef. Although the content of connective tissue in elderly cattle is reduced, the activity of muscle endogenous protease inhibitors is higher, the interaction between protein molecules is increased, and the content of collagen fibers is reduced. Under heating or acid-base conditions, collagen fibers contract and the meat is tender Degree becomes smaller. Therefore, under normal circumstances, the tenderness of old beef is lower than that of young beef.
2. Genotype and growth environment
The genotype of cattle will affect tenderness. The tenderness of different breeds of cattle will also differ, but in fact environmental factors also play a big role. The tenderness of beef grown in the wild or frequently stocked is lower than that of captive and rarely stocked beef. Tenderness of meat depends on genotype 30%, and 70% depends on its growth environment. The difference in tenderness of different varieties of beef is equal to or slightly lower than that of the same variety. 46% of all beef varieties are affected by genotype and 54% by environmental factors. From the research results, we can see that the influence of environmental factors on beef tenderness is higher than that of genotypes on beef tenderness. Therefore, in the breeding process of cattle, genotype cattle with high tenderness can be selected as well as on suitable cattle. Carry out.
3. Cooking method and heating temperature
By changing the cooking method and heating temperature of beef, the tenderness of beef can be improved. When beef is cooked, stewed, and roasted in the cooking process, the tenderness of the meat is higher than that of fried, fried, and grilled. Heating can denature proteins and affect tenderness. The difference in heating temperature will also affect the tenderness of beef. Through experiments, the heating temperature is controlled to 60 ℃ and 68 ℃, and other conditions remain unchanged. Studies have shown that beef tenderness at 60 ℃ is higher. In addition, it takes less time to cook muscles with less marbling, while it takes longer to cook muscles with more marbling. When the center temperature of the beef is 71-77 ° C, the optimal cooking temperature is reached, and the beef taste is the best at this time.
4. Collagen
Collagen is an important part of beef connective tissue, which has a great influence on the tenderness of meat. Under normal circumstances, muscles that contain more collagen are less tender. Older cow muscles contain more collagen than younger cow muscles, but their tenderness is lower than that of younger cows. However, this is not the case. In fact, the interaction between collagen molecules determines the degree of tenderness. HillF (1991) divided cattle into three groups according to age, namely young, middle and old groups, and then measured their collagen content. From the results of the study, the collagen content of the middle-aged group was lower than that of the young and old groups. It can be seen that there is no obvious correlation between the total collagen content and the age of the cow. As the age of the cow increases, the force between the collagen molecules increases, so the collagen structure is firmer, resulting in a decrease in the tenderness of the meat.
Second, the physical method of beef tenderization
1. Mechanical tenderization method
Refers to the use of mechanical force to tenderize meat. The principle of tenderization is to destroy muscle fiber cells and connective tissue between muscles by external force, separate actin and myosin, and destroy the structure of meat, increase water retention and adhesion, thus Improve the tenderness of the meat. The mechanical tenderization method is suitable for meat with low tenderness. The tenderization process takes a long time and can increase tenderness by 20% to 50%. It can be divided into rolling and tenderizing methods, reorganizing and tenderizing methods, and the like. The method of tumbling and tenderizing is to marinate the meat first, and then tumbling and damaging the muscle fibers, thereby enhancing the beef's water power and improving the tenderness. The reorganization and tenderization method is to cut the meat into small pieces of meat, and then mix well with phosphate and salt until it is shaped.
2. Ultra-high pressure technology tenderization method
Under ultra-high pressure, the force between beef myosin and actin decreases. At an ambient temperature of 20 ° C, increasing the pressure can increase the pH value, and the increase in acidity will soften the connective tissue in the cell membrane. ; At the same time, lysosomes rupture under high pressure to produce proteases, resulting in the breakdown of structural proteins of muscle fibers. Under the combined effect of these two aspects, the tenderness of beef increases. Bai Yanhong [15] (2004) studied the sensory characteristics, structure and shear force of cattle and sheep muscles under ultra-high pressure, as well as the tenderization of these factors on cattle and sheep muscles. Studies have shown that under the conditions of ultra-high pressure treatment, the shear force of beef and sheep muscles is significantly reduced, and the ultra-high pressure treatment has a good tenderization effect and a uniform effect, which can improve the flavor and color of the meat.
3. Ultrasonic tenderization method
Ultrasonic tenderization is rarely studied at present. It uses sound waves to exert force on meat that needs to be tenderized when immersed in water, causing muscle fibers to break, lysosomes to rupture, resulting in increased soluble protein concentration and changes in tissue structure. This process takes a short time to tenderize the meat quickly. Ultrasonic tenderization is a new technology, which has the advantages of safety and economy, and can improve the taste, texture and water holding capacity of meat.
4. Electrical stimulation tenderization method
The principle of electrical stimulation tenderization method is to use current to stimulate the meat, which causes the muscle fiber structure to be broken, and the water retention is increased to improve the tenderness of the meat. Electrical stimulation accelerates the glycolysis reaction that occurs in the meat, lowers the pH of the meat, promotes protein decomposition, and increases the tenderness of the meat. The electric stimulation tenderization method has the advantages of simplicity and high efficiency, and can improve the appearance, color and taste of meat. However, due to the dangers of the electrical stimulation tenderization method, it is used less.
Three, chemical methods of beef tenderization
1. Carbonate tenderization method
All carbonates include sodium carbonate and sodium bicarbonate, etc. The tenderization method is to prepare it into a solution (1% to 2%), and then inject it into the meat block, or put the meat block that needs to be tenderized into the solution in. Carbonate solution is usually alkaline, it can increase the pH of the meat, destroy the structure of the meat, enhance water retention, thereby increasing the tenderness, and improving the color of the meat products, etc., but it can also cause some nutrient loss.
2. Softening method of cysteine hydrochloride
The principle of tenderization of cysteine hydrochloride is to break down the -SH group of the active group of the enzyme molecule, so that the structure of the enzyme molecule is destroyed, the cystolytic enzyme system is activated, and the release of active protease is promoted. , And ultimately improve the tenderness of meat products.
3. Polyphosphate softening method
In the production and processing of meat products, the addition of polyphosphate can inhibit the oxidation of fat, increase the tenderness of the meat, make the taste excellent, improve the sliceability and water retention. The tenderization method is to prepare it into a solution and then inject it into the meat pieces. Generally, the amount added is 0.125% to 0.375%, less than 0.5%. Its mechanism of action: polyphosphate is alkaline, which can increase the pH of meat; increase the solubility of myosin; increase the electrostatic repulsion of protein; promote the dissociation of actin. This method can significantly improve the texture of the meat.
4. Biological method of beef tenderization
1. Endogenous protease
Endogenous proteases include calcium activating enzyme and cathepsin. Calcium activating enzyme has a good tenderizing effect. It is a neutral protease with stable properties. It exists near the Z disk of muscle fibers and on the sarcoplasmic reticulum. Can decompose myofibrillar protein. The principle of tenderization is: after the animal is slaughtered, the structure of the sarcoplasmic reticulum is destroyed, the concentration of calcium ions rises, activates calcium-activated enzymes, cleaves the z-line, releases myofilaments, decomposes myofibrillar protein, destroys its structure, and thus improves The tenderness of the meat.
2. Exogenous protease
Commonly used exogenous proteases for tenderizing meat include vegetable proteases (Fig protease, bromelain, papain, etc.), microbial proteases (root enzyme protease, rice koji protease, alkaline protease of Bacillus subtilis, etc.), animal proteases (pancreas Protease) and other categories. The properties of these enzymes are stable, and the tenderization effect of plant proteases is better. Exogenous proteases can decompose collagen and fibrin, destroy the spatial structure, increase the water retention of meat, and thus increase the tenderness, which can improve the flavor and taste of meat products. At present, papain is the main type of tenderizer in the market. The principle of tenderization is to improve the tenderness of beef by hydrolyzing protein molecules. Moreover, due to its low price, ginger protease has attracted the attention of researchers at home and abroad. There are also enzymes extracted from some bacteria and fungi, such as Bacillus subtilis protease, streptavidin and hydrolytic protease. Many of these enzymes have the function of hydrolyzing proteins, which can improve the tenderness of meat. In general, exogenous proteases have the advantages of safety and hygiene, which can improve the tenderness and taste of beef and reduce the loss of nutritional value.
3. Hormone tenderization method
The method of hormone tenderization is to inject appropriate amount of hormone preparations such as epinephrine and insulin into the body before the cattle are slaughtered. Injecting hormones can accelerate the rate of sugar metabolism, keep the content of glycogen and lactic acid in meat at a low level, increase the pH of meat, increase the amount of myosin and increase the tenderness of meat.
V. Outlook
Beef has high nutritional value, and the benefits of its food value have been paid more and more attention by people. Because of the importance, people attach to beef quality, beef tenderization is also becoming more important. There are many beef tenderization methods, but some tenderization methods are not suitable for commercial production, so it should be continuously researched and improved; during the production and processing process, it is necessary to determine the appropriate tenderization method from the reality, through physical, biological, chemical aspects Tenderize the meat, increase the value of beef, promote the vigorous development of the beef market, and meet people's demand for beef taste and nutrition.
