1. Classification of meat products
1) By raw materials: products made from livestock meat, poultry meat, fish, and game.
2) By processing techniques: cured products, braised products, smoked and grilled products, dried products, fried products, sausage products, ham products, and canned meat products.
3) By origin: Chinese-style meat products and Western-style meat products.
4) By processing degree: unheated meat products and heated meat products.
2. Significance of meat product processing
1) To kill various microorganisms that contaminate raw meat to ensure food hygiene and improve food safety.
2) To destroy or inhibit the activity of enzymes to extend the storage period of products.
3) To improve flavor and texture to enhance the color, aroma, and taste of products.
4) To increase nutritional components and make up for certain deficiencies in raw meat to improve the nutritional value of products.
5) To turn most meat products into ready-to-eat convenience foods to promote disinfection and increase production.
3. Thawing
Purpose: To restore the original tissue structure of frozen raw materials as much as possible.
Four elements of thawing: temperature, humidity, time, and quality.
Factories should consider various factors such as the size of the thawing warehouse, actual production volume, existing equipment, and product cost to determine the thawing method to use.
1) Common thawing methods
① Natural thawing, also known as air thawing, with an ambient temperature of 12-15℃, relative humidity of 80-90%, and air flow rate of 1-1.5m/s. Air thawing results in significant blood water loss, with pork losing about 3%, beef about 5%, and chicken up to 8%.
② Running water thawing, with water temperature not exceeding 30℃. Running water thawing causes less weight loss but greater loss of nutrients. Japan uses still water thawing, which results in less nutrient loss, saves costs, and keeps the meat temperature between -2 and +2℃ after thawing.
③ Steam thawing, which causes severe denaturation of the surface protein of raw materials.
④ Microwave thawing, a popular thawing method in recent years, but with a large initial investment.
Characteristics of microwave thawing:
① Fast thawing speed and energy saving;
② Preservation of nutrients and improvement of meat quality;
③ Rapid passage through cells and destruction of cell reproduction areas, increasing the yield rate;
④ High energy utilization rate and uniform thawing;
⑤ Safety and hygiene;
⑥ Simple operation and small floor space;
⑦ Improved working environment, realization of assembly line production, and reduction of labor intensity.
The center temperature of the thawed raw meat should be 0℃.
2) Precautions for thawing
1) Do not stack too much meat;
2) Prevent cross-contamination;
3) Do not allow the ambient temperature to be too high;
4) Pay attention to the hygiene of tools, and thoroughly wash and disinfect them after each use;
5) Process the thawed meat immediately and do not repeatedly freeze and thaw it.
4. Cutting
Purpose: To remove tendons, fat, cartilage, and lymph nodes.
Temperature: The temperature management of raw materials after cutting directly affects the quality of subsequent product processing. Generally, the temperature of the cut meat should be kept below 6℃, so the time the raw materials stay in this process should not be too long, the sooner the better. Considering human health factors, the room temperature of 8-12℃ is the best. After cutting, the full bucket of meat should be sent to storage at 0-4℃ immediately.
The large pieces of lean meat from the hind legs of frozen pigs, without visible fat or tendons, generally have 75% tissue water, 4% fat, and 21% protein, and are used to produce high-end starch-free ham products. The small pieces of lean meat, with visible fat of 5%, generally have 72% tissue water, 8% fat, and 20% protein, and are used to produce premium smoked and boiled sausages. The separated lean meat with visible fat content of 15%, general tissue moisture of 63%, fat of 20%, and protein of 17% is used to produce ordinary smoked cooked sausages; visible fat content of 20%, general tissue moisture of 55%, fat of 28%, and protein of 17% is used to produce ordinary smoked cooked sausages; visible fat content of 30%, general tissue moisture of 55%, fat of 35%, and protein of 15% is used to produce ordinary smoked cooked sausages; connective tissue protein accounts for 7% to 30% of the edible meat protein depending on the pig part.
5. Curing
1) The role and mechanism of curing
The role of curing: preservation, stabilization of meat color, improvement of meat water-holding capacity, and enhancement of meat flavor.
The mechanism of meat curing mainly occurs through the penetration and diffusion of the curing solution.
2) Curing methods
The traditional methods of meat curing are wet curing and dry curing, with the environmental temperature controlled at 3 to 5°C. Currently, the wet curing method has been improved by using tumbling or injection to quickly cure the meat, which not only saves time but also improves work efficiency, although the product flavor is slightly inferior to the traditional method. For example, Italian Parma ham and Chinese Jinhua ham both use the traditional dry curing method.
6. Grinding
Grinding refers to the process of using a meat grinder to cut meat or fat into small pieces to meet processing requirements. The grinding operation directly affects the quality of the final product.
1) Preparation before grinding
① Selection of the meat grinder
It is best to use a three-stage meat grinder (which has two sets of knives between three metal screens).
② Inspection of the meat grinder
Check whether the metal screens and knife edges fit properly to prevent gaps that could cause meat tissue membranes and connective tissues to wrap around the knife edges, affecting the cutting effect, damaging the meat tissue cells, weakening the binding force of added fat, and resulting in poor adhesion, which affects the quality of the final product.
③ Cleaning of the meat grinder
After inspection, proceed with cleaning operations in accordance with the operating procedures. Before use, make sure to cool it down.
④ Preparation of raw materials
Before grinding, try to cut the raw meat and fat into small pieces as much as possible, and cool the meat and fat to below 5°C.
2) Grinding operation
① Adjustment of the meat grinder
Select the appropriate hole plate according to the process design requirements, and the tightness of the screw cap should be appropriate (the fit between the knife edge and the screen). If it is too tight, there will be excessive friction and the meat temperature will rise quickly; if it is too loose, the fascia is likely to wrap around the blade, affecting the texture of the ground meat.
② Method of grinding
The proportion of meat added should be appropriate to prevent excessive movement of the meat in the hopper, causing the temperature to rise and ultimately affecting the binding force of the meat. When grinding fat, add it in small amounts to prevent the temperature from rising and causing the fat to melt, which affects product quality.
③ Cleaning
After each operation, the meat grinder should be cleaned promptly to prevent bacterial growth. First, use hot water around 45°C to remove oil stains, and finally use hot water at 80°C to rinse and disinfect.
④ Safety precautions
During the grinding operation, pay attention to hand protection, especially when operating small machinery. Use a meat pusher to feed the meat.
⑤ Rotational speed of the meat grinder
It is generally believed that a higher rotational speed means higher efficiency, but this is incorrect. Research shows that when the rotational speed of the meat grinder is controlled at 150 r/min, the product temperature and pH value changes are small, and the meat emulsion and free water are reduced.
7. Chopping
Chopping: refers to the process of using a chopper to evenly mix the meat emulsion or improve the emulsification and adhesion of the meat, while giving the product a better texture and flavor.
1) Preparation before chopping
1) Inspection and cleaning of the chopper
First, check if the knife is sharp. A dull knife will affect the emulsification effect of chopping, causing the product to be oily and have a rough texture. It is best to set the grinding time according to the actual production situation. Secondly, make sure the knife is securely fastened to the knife shaft to prevent it from flying out during operation and causing an accident. Then, check the distance between the knife and the rotating disc. It is best to have a distance equivalent to the thickness of two sheets of kraft paper. If the distance is too wide, it will affect the chopping effect; if it is too narrow, it may cause damage to the knife. Finally, clean it thoroughly and add ice to cool it down for later use.
2) Preparation of raw meat and fat
Generally, lean meat and fat are processed separately during chopping. The temperature of lean meat should be controlled below 5℃, and that of fat below 2℃. If there is still some time before the chopping operation, it is best to store the raw materials in a low-temperature warehouse.
3) Use of ice
It is best to use ice shavings instead of ice cubes during production. Ice cubes can increase the wear of the chopping machine's knife blades and reduce the emulsification effect of the meat.
2) Pre-chopping operations
1) Basic operations
First, add the lean meat and spread it evenly. Then, add 2/3 of the ice and seasonings and chop at high speed. When the meat temperature reaches 4-6℃, add the fat, egg whites, and 1/3 of the ice and continue to chop at high speed. When the meat temperature reaches 7-8℃, add the spices and chop evenly until it is ready to be removed from the machine. Generally, the temperature of chicken products should be controlled within 10℃ when removed from the machine, and that of pork products within 12℃.
2) Factors affecting the chopping effect
① The influence of knife speed
Generally, the faster the chopping knife speed, the better the chopping effect (emulsification, viscosity, elasticity), the better the water retention of the meat, and the less the juice exudation of the meat.
② The influence of time
Generally, the longer the chopping time, the better the emulsification effect and viscosity of the meat. However, if the time is too long, the temperature of the meat will rise faster, which will affect the emulsification effect of the product and reduce its viscosity, as well as damage the cell structure.
③ The combined influence of knife speed and time
Generally, the experience data shows that when the knife speed is controlled between 2880 and 4700 r/min, the chopping effect and temperature are relatively reasonable.
3) Addition of fat
Generally, the separation (oil exudation) of fat is largely due to the dispersion state, quality of the fat, and excessively high chopping temperature.
8. Mixing
Mixing refers to the process of blending raw materials evenly through mechanical agitation in accordance with the product's technological requirements.
1) Preparation before mixing
First, check if the machinery is operating normally; then, carefully clean the mixing blades and the mixing tank with warm water and disinfect them; finally, prepare the raw materials as per the product's technological requirements.
2) Mixing operation
After the raw materials are prepared, the mixing operation begins. First, add lean meat and start mixing, then add seasonings and spices, and finally add fat. Generally, a mixing time of 5 to 10 minutes is appropriate.
3) Cleaning
After the mixing is completed, clean all parts of the mixer promptly, especially the shaft and the base of the blades. If not cleaned thoroughly, bacteria can easily multiply. When cleaning the meat grinder and the mixer, first use 45% hot water to clean them thoroughly, and then rinse with 80°C hot water for disinfection.
4) Precautions for mixing
1) During the mixing process of meat products, when controlling the protein and moisture content of the meat, not only the weight of the added protein powder and water should be considered, but also the protein and tissue moisture of the raw meat itself.
2) The combination of raw meat is very important for the product's structure. Improper addition of fat and lean meat during raw material usage can lead to dry texture and excessive oiliness in the product.
3) Improper combination of water and additives can cause water leakage and excessive moisture in the product.
4) Employees are required to calibrate the measuring instruments daily. They should use standard weights to calibrate floor scales and electronic platform scales. If any inaccuracy is found, stop using them and notify the relevant professionals for repair before use. During operation, strictly adhere to the standard for the addition of each batch of raw materials, and no positive or negative deviations are allowed. Temperature control: strictly follow the standard temperature specified and do not make any arbitrary changes.
1) By raw materials: products made from livestock meat, poultry meat, fish, and game.
2) By processing techniques: cured products, braised products, smoked and grilled products, dried products, fried products, sausage products, ham products, and canned meat products.
3) By origin: Chinese-style meat products and Western-style meat products.
4) By processing degree: unheated meat products and heated meat products.
2. Significance of meat product processing
1) To kill various microorganisms that contaminate raw meat to ensure food hygiene and improve food safety.
2) To destroy or inhibit the activity of enzymes to extend the storage period of products.
3) To improve flavor and texture to enhance the color, aroma, and taste of products.
4) To increase nutritional components and make up for certain deficiencies in raw meat to improve the nutritional value of products.
5) To turn most meat products into ready-to-eat convenience foods to promote disinfection and increase production.
3. Thawing
Purpose: To restore the original tissue structure of frozen raw materials as much as possible.
Four elements of thawing: temperature, humidity, time, and quality.
Factories should consider various factors such as the size of the thawing warehouse, actual production volume, existing equipment, and product cost to determine the thawing method to use.
1) Common thawing methods
① Natural thawing, also known as air thawing, with an ambient temperature of 12-15℃, relative humidity of 80-90%, and air flow rate of 1-1.5m/s. Air thawing results in significant blood water loss, with pork losing about 3%, beef about 5%, and chicken up to 8%.
② Running water thawing, with water temperature not exceeding 30℃. Running water thawing causes less weight loss but greater loss of nutrients. Japan uses still water thawing, which results in less nutrient loss, saves costs, and keeps the meat temperature between -2 and +2℃ after thawing.
③ Steam thawing, which causes severe denaturation of the surface protein of raw materials.
④ Microwave thawing, a popular thawing method in recent years, but with a large initial investment.
Characteristics of microwave thawing:
① Fast thawing speed and energy saving;
② Preservation of nutrients and improvement of meat quality;
③ Rapid passage through cells and destruction of cell reproduction areas, increasing the yield rate;
④ High energy utilization rate and uniform thawing;
⑤ Safety and hygiene;
⑥ Simple operation and small floor space;
⑦ Improved working environment, realization of assembly line production, and reduction of labor intensity.
The center temperature of the thawed raw meat should be 0℃.
2) Precautions for thawing
1) Do not stack too much meat;
2) Prevent cross-contamination;
3) Do not allow the ambient temperature to be too high;
4) Pay attention to the hygiene of tools, and thoroughly wash and disinfect them after each use;
5) Process the thawed meat immediately and do not repeatedly freeze and thaw it.
4. Cutting
Purpose: To remove tendons, fat, cartilage, and lymph nodes.
Temperature: The temperature management of raw materials after cutting directly affects the quality of subsequent product processing. Generally, the temperature of the cut meat should be kept below 6℃, so the time the raw materials stay in this process should not be too long, the sooner the better. Considering human health factors, the room temperature of 8-12℃ is the best. After cutting, the full bucket of meat should be sent to storage at 0-4℃ immediately.
The large pieces of lean meat from the hind legs of frozen pigs, without visible fat or tendons, generally have 75% tissue water, 4% fat, and 21% protein, and are used to produce high-end starch-free ham products. The small pieces of lean meat, with visible fat of 5%, generally have 72% tissue water, 8% fat, and 20% protein, and are used to produce premium smoked and boiled sausages. The separated lean meat with visible fat content of 15%, general tissue moisture of 63%, fat of 20%, and protein of 17% is used to produce ordinary smoked cooked sausages; visible fat content of 20%, general tissue moisture of 55%, fat of 28%, and protein of 17% is used to produce ordinary smoked cooked sausages; visible fat content of 30%, general tissue moisture of 55%, fat of 35%, and protein of 15% is used to produce ordinary smoked cooked sausages; connective tissue protein accounts for 7% to 30% of the edible meat protein depending on the pig part.
5. Curing
1) The role and mechanism of curing
The role of curing: preservation, stabilization of meat color, improvement of meat water-holding capacity, and enhancement of meat flavor.
The mechanism of meat curing mainly occurs through the penetration and diffusion of the curing solution.
2) Curing methods
The traditional methods of meat curing are wet curing and dry curing, with the environmental temperature controlled at 3 to 5°C. Currently, the wet curing method has been improved by using tumbling or injection to quickly cure the meat, which not only saves time but also improves work efficiency, although the product flavor is slightly inferior to the traditional method. For example, Italian Parma ham and Chinese Jinhua ham both use the traditional dry curing method.
6. Grinding
Grinding refers to the process of using a meat grinder to cut meat or fat into small pieces to meet processing requirements. The grinding operation directly affects the quality of the final product.
1) Preparation before grinding
① Selection of the meat grinder
It is best to use a three-stage meat grinder (which has two sets of knives between three metal screens).
② Inspection of the meat grinder
Check whether the metal screens and knife edges fit properly to prevent gaps that could cause meat tissue membranes and connective tissues to wrap around the knife edges, affecting the cutting effect, damaging the meat tissue cells, weakening the binding force of added fat, and resulting in poor adhesion, which affects the quality of the final product.
③ Cleaning of the meat grinder
After inspection, proceed with cleaning operations in accordance with the operating procedures. Before use, make sure to cool it down.
④ Preparation of raw materials
Before grinding, try to cut the raw meat and fat into small pieces as much as possible, and cool the meat and fat to below 5°C.
2) Grinding operation
① Adjustment of the meat grinder
Select the appropriate hole plate according to the process design requirements, and the tightness of the screw cap should be appropriate (the fit between the knife edge and the screen). If it is too tight, there will be excessive friction and the meat temperature will rise quickly; if it is too loose, the fascia is likely to wrap around the blade, affecting the texture of the ground meat.
② Method of grinding
The proportion of meat added should be appropriate to prevent excessive movement of the meat in the hopper, causing the temperature to rise and ultimately affecting the binding force of the meat. When grinding fat, add it in small amounts to prevent the temperature from rising and causing the fat to melt, which affects product quality.
③ Cleaning
After each operation, the meat grinder should be cleaned promptly to prevent bacterial growth. First, use hot water around 45°C to remove oil stains, and finally use hot water at 80°C to rinse and disinfect.
④ Safety precautions
During the grinding operation, pay attention to hand protection, especially when operating small machinery. Use a meat pusher to feed the meat.
⑤ Rotational speed of the meat grinder
It is generally believed that a higher rotational speed means higher efficiency, but this is incorrect. Research shows that when the rotational speed of the meat grinder is controlled at 150 r/min, the product temperature and pH value changes are small, and the meat emulsion and free water are reduced.
7. Chopping
Chopping: refers to the process of using a chopper to evenly mix the meat emulsion or improve the emulsification and adhesion of the meat, while giving the product a better texture and flavor.
1) Preparation before chopping
1) Inspection and cleaning of the chopper
First, check if the knife is sharp. A dull knife will affect the emulsification effect of chopping, causing the product to be oily and have a rough texture. It is best to set the grinding time according to the actual production situation. Secondly, make sure the knife is securely fastened to the knife shaft to prevent it from flying out during operation and causing an accident. Then, check the distance between the knife and the rotating disc. It is best to have a distance equivalent to the thickness of two sheets of kraft paper. If the distance is too wide, it will affect the chopping effect; if it is too narrow, it may cause damage to the knife. Finally, clean it thoroughly and add ice to cool it down for later use.
2) Preparation of raw meat and fat
Generally, lean meat and fat are processed separately during chopping. The temperature of lean meat should be controlled below 5℃, and that of fat below 2℃. If there is still some time before the chopping operation, it is best to store the raw materials in a low-temperature warehouse.
3) Use of ice
It is best to use ice shavings instead of ice cubes during production. Ice cubes can increase the wear of the chopping machine's knife blades and reduce the emulsification effect of the meat.
2) Pre-chopping operations
1) Basic operations
First, add the lean meat and spread it evenly. Then, add 2/3 of the ice and seasonings and chop at high speed. When the meat temperature reaches 4-6℃, add the fat, egg whites, and 1/3 of the ice and continue to chop at high speed. When the meat temperature reaches 7-8℃, add the spices and chop evenly until it is ready to be removed from the machine. Generally, the temperature of chicken products should be controlled within 10℃ when removed from the machine, and that of pork products within 12℃.
2) Factors affecting the chopping effect
① The influence of knife speed
Generally, the faster the chopping knife speed, the better the chopping effect (emulsification, viscosity, elasticity), the better the water retention of the meat, and the less the juice exudation of the meat.
② The influence of time
Generally, the longer the chopping time, the better the emulsification effect and viscosity of the meat. However, if the time is too long, the temperature of the meat will rise faster, which will affect the emulsification effect of the product and reduce its viscosity, as well as damage the cell structure.
③ The combined influence of knife speed and time
Generally, the experience data shows that when the knife speed is controlled between 2880 and 4700 r/min, the chopping effect and temperature are relatively reasonable.
3) Addition of fat
Generally, the separation (oil exudation) of fat is largely due to the dispersion state, quality of the fat, and excessively high chopping temperature.
8. Mixing
Mixing refers to the process of blending raw materials evenly through mechanical agitation in accordance with the product's technological requirements.
1) Preparation before mixing
First, check if the machinery is operating normally; then, carefully clean the mixing blades and the mixing tank with warm water and disinfect them; finally, prepare the raw materials as per the product's technological requirements.
2) Mixing operation
After the raw materials are prepared, the mixing operation begins. First, add lean meat and start mixing, then add seasonings and spices, and finally add fat. Generally, a mixing time of 5 to 10 minutes is appropriate.
3) Cleaning
After the mixing is completed, clean all parts of the mixer promptly, especially the shaft and the base of the blades. If not cleaned thoroughly, bacteria can easily multiply. When cleaning the meat grinder and the mixer, first use 45% hot water to clean them thoroughly, and then rinse with 80°C hot water for disinfection.
4) Precautions for mixing
1) During the mixing process of meat products, when controlling the protein and moisture content of the meat, not only the weight of the added protein powder and water should be considered, but also the protein and tissue moisture of the raw meat itself.
2) The combination of raw meat is very important for the product's structure. Improper addition of fat and lean meat during raw material usage can lead to dry texture and excessive oiliness in the product.
3) Improper combination of water and additives can cause water leakage and excessive moisture in the product.
4) Employees are required to calibrate the measuring instruments daily. They should use standard weights to calibrate floor scales and electronic platform scales. If any inaccuracy is found, stop using them and notify the relevant professionals for repair before use. During operation, strictly adhere to the standard for the addition of each batch of raw materials, and no positive or negative deviations are allowed. Temperature control: strictly follow the standard temperature specified and do not make any arbitrary changes.
