Extrusion in food processing consists of forcing soft mixed ingredients through an opening in a perforated plate or die designed to produce the required shape. The extruded food is then cut to a specific size by blades. The machine which forces the mix through the die is an extruder, and the mix is known as the extrudate. The extruder is typically a large, rotating screw tightly fitting within a stationary barrel, at the end of which is the die.
Extrusion enables mass production of food via a continuous, efficient system that ensures uniformity of the final product. These include some pasta, breads (croutons, bread sticks, and flat breads), many breakfast cereals and ready-to-eat snacks, confectionery, pre-made cookie dough, some baby foods, full-fat soy, textured vegetable protein, some beverages, and dry and semi-moist pet foods. Food products manufactured using extrusion usually have a high starch content.
Process
[
edit
]
A non-vacuum short goods pasta extruder fromIn the extrusion process, raw materials are first ground to the correct particle size, usually the consistency of coarse flour. The dry mix is passed through a pre-conditioner, in which other ingredients are added depending on the target product; these may be liquid sugar, fats, dyes, meats or water. Steam is injected to start the cooking process, and the preconditioned mix (extrudate) is then passed through an extruder. The extruder is a large, rotating screw tightly fitting within a stationary barrel, at the end of which is the die.[1] The extruder's rotating screw forces the extrudate towards and through the die. The extrudate is in the extruder for the residence time.[citation needed]
Many extruded products puff and change texture as they are extruded because of the reduction of forces and release of moisture and heat.[1] The extent to which it does so is known as the expansion ratio. The extrudate is cut to the desired length by blades at the output of the extruder, which rotate about the die openings at a specific speed. The product is then cooled and dried, becoming rigid while maintaining porosity.[citation needed]
Cooking takes place within the extruder, where the product produces its own friction and heat due to the pressure generated (10'20 bar). The process can induce both protein denaturation and starch gelatinization under some conditions.
Many food extrusion processes involve a high temperature for a short time.[1] Important factors of the extrusion process are the composition of the extrudate, screw length and rotating speed, barrel temperature and moisture, die shape, and rotating speed of the blades. These are controlled based on the desired product to ensure uniformity of the output.[citation needed]
Moisture is the most important of these factors, and affects the mix viscosity, acting to plasticize the extrudate. Increasing moisture will decrease viscosity, torque, and product temperature, and increase bulk density. This will also reduce the pressure at the die. Most extrusion processes for food processing are carried out at low to intermediate moisture (moisture level below 40%). High-moisture extrusion is known as wet extrusion, but it was not used much before the introduction of twin screw extruders (TSE), which have a more efficient conveying capability. The most important rheological factor in the wet extrusion of high-starch extrudate is temperature.[2]
The amount of salt in the extrudate may determine the colour and texture of some extruded products. The expansion ratio and airiness of the product depend on the salt concentration in the extrudate, possibly as a result of a chemical reaction between the salt and the starches in the extrudate. Colour changes as a result of salt concentration may be caused by "the ability of salt to change the water activity of the extrudate and thus change the rate of browning reactions". Salt is also used to distribute minor ingredients, such as food colours and flavours, after extrusion; these are more evenly distributed over the product's surface after being mixed with salt.[3]
History
[
edit
]
Dry pasta manufacturing line from sThe first extruder was designed to manufacture sausages in the s.[4] Dry pasta and breakfast cereals have been produced by extrusion since the s,[2] and the method has been applied to pet food production since the s (first extruded dog food: Purina Dog Chow in , and first extruded cat food: Purina Friskies in ).[4] Some domestic kitchen appliances such as meat grinders and some types of pasta makers use extrusion. Pastry bags (piping bags), squeezed by hand, operate by extrusion.[citation needed]
Effects
[
edit
]
Extrusion enables mass production of food via a continuous, efficient system that ensures uniformity of the final product. This is achieved by controlling various aspects of the extrusion process. It has also enabled the production of new processed food products and "revolutionized many conventional snack manufacturing processes".[5] The extrusion process results in "chemical reactions that occur within the extruder barrel and at the die".[6] Extrusion has the following effects:[7][8][9]
The material of which an extrusion die is made can affect the final product. Rough bronze dies on pasta extruders produce a rougher surface than smooth stainless steel dies, considered to make more liquid pasta sauces adhere better;[11] pasta made this way is labelled "bronze die" pasta to indicate a premium product.[12]
Front of a die for making elbow macaroni
Back of the same plastic die
Old metal dies for pasta, showing bottom and top of the dies
The effects of "extrusion cooking on nutritional quality are ambiguous",[13] as extrusion may change carbohydrates, dietary fibre, the protein and amino acid profile, vitamins, and mineral content of the extrudate in a manner that is beneficial or harmful.[13]
High-temperature extrusion for a short duration "minimizes losses in vitamins and amino acids".[1] Extrusion enables mass production of some food, and will "denature antinutritional factors",[1] such as destroying toxins or killing microorganisms. It may also improve "protein quality and digestibility",[1] and affects the product's shape, texture, colour, and flavour.[1]
It may also cause the fragmentation of proteins, starches, and non-starch polysaccharides to create "reactive molecules that may form new linkages not found in nature".[6] This includes Maillard reactions which reduce the nutritional value of the proteins.[13] Vitamins with heat lability may be destroyed.[13] As of , little is known about the stability or bioavailability of phytochemicals involved in extrusion.[6] Nutritional quality has been found to improve with moderate conditions (short duration, high moisture, low temperature), whereas a negative effect on nutritional quality of the extrudate occurs with a high temperature (at least 200 °C), low moisture (less than 15%), or improper components in the mix.[13]
A research paper indicates that use of non-traditional cereal flours, such as amaranth, buckwheat or millet, may be used to reduce the glycemic index of breakfast cereals produced by extrusion.[14] The extrudate using these cereal flours exhibits a higher bulk and product density, has a similar expansion ratio, and has "a significant reduction in readily digestible carbohydrates and slowly digestible carbohydrates".[14] A paper states that replacing 5% to 15% of the wheat flour and white flour with dietary fibre in the extrudate breakfast cereal mix significantly reduces "the rate and extent of carbohydrate hydrolysis of the extruded products",[10] which increased the level of slowly digested carbohydrates and reduced the level of quickly digested carbohydrates.[10]
Products
[
edit
]
Extrusion has enabled the production of new processed food products and "revolutionized many conventional snack manufacturing processes".[5]
The various types of food products manufactured by extrusion typically have a high starch content.[1] Directly expanded types include breakfast cereals and corn curls, and are made in high-temperature, low-moisture conditions under high shear. Unexpanded products include pasta, which is produced at intermediate moisture (about 40%) and low temperature. Texturized products include meat analogues, which are made using plant proteins ("textured vegetable protein") and a long die to "impart a fibrous, meat-like structure to the extrudate",[4] and fish paste.[15]
Cheese curls, a directly expanded snack food
Pasta, an unexpanded food
Meat alternative, a texturized food
Some processed cheeses and cheese analogues are also made by extrusion. Processed cheeses extruded with low moisture and temperature "might be better suited for manufacturing using extrusion technology" than those at high moisture or temperature. Lower moisture cheeses are firmer and chewier, and cheddar cheese with low moisture and an extrusion temperature of 80 °C was preferred by subjects in a study to other extruded cheddar cheese produced under different conditions.[16] An extrudate mean residence time of about 100 seconds can produce "processed cheeses or cheese analogues of varying texture (spreadable to sliceable)".[17]
Confectionery made via extrusion includes chewing gum, liquorice, and toffee.[15] Other food products often produced by extrusion include some breads (croutons, bread sticks, and flat breads), various ready-to-eat snacks, pre-made cookie dough, some baby foods, some beverages, and dry and semi-moist pet foods. Specific examples include cheese curls, macaroni, Fig Newtons, jelly beans, sevai, and some french fries.[18]
Extrusion is also used to modify starch and to pellet animal feed.[citation needed]
See also
[
edit
]
References
[
edit
]
Further reading
[
edit
]
In the realm of food processing, efficiency, consistency, and versatility are paramount. Snack food extruder machinesfood extruder machines have emerged as indispensable tools for manufacturers seeking to meet the ever-growing demand for a wide variety of snack foods. From crunchy chips to savory puffs, these machines offer a multitude of benefits that significantly enhance the production process and the quality of the final product.
One of the primary benefits of choosing a snack food extruder machine is the enhanced efficiency it brings to the production process. These machines are designed to automate the extrusion process, significantly reducing the need for manual labor and streamlining production. With precise control over parameters such as temperature, pressure, and speed, manufacturers can consistently produce large quantities of snack foods in a shorter time frame, increasing overall efficiency and output.
Consistency is key in the food industry, particularly when it comes to snack foods. Snack food Processing Line excel in delivering consistent quality products batch after batch. By maintaining strict control over the extrusion process, these machines ensure uniformity in texture, shape, and flavor, eliminating variations that can compromise the overall quality of the product. Whether it's crispy chips or airy puffs, customers can expect the same great taste and texture every time they indulge in their favorite snack.
Another significant benefit of snack food extruder machines is their versatility in product development. These machines can handle a wide range of ingredients, allowing manufacturers to experiment with different recipes and create an extensive array of snack food varieties. From traditional potato-based snacks to innovative blends of grains and pulses, the possibilities are endless. Additionally, snack food extruder machines can produce snacks in various shapes and sizes, catering to diverse consumer preferences and market trends.
Investing in a snack food extruder machine can prove to be highly cost-effective for manufacturers in the long run. While the initial capital outlay may seem significant, the efficiency and productivity gains achieved with these machines can lead to substantial cost savings over time. Reduced labor costs, increased production output, and minimized waste contribute to improved profitability and competitiveness in the market. Moreover, the versatility of snack food extruder machines allows manufacturers to adapt to changing consumer demands and explore new market opportunities without the need for additional equipment.
Maintaining high standards of food safety and hygiene is non-negotiable in the food industry. Snack food extruder machines are designed with sanitation in mind, featuring easy-to-clean surfaces and components that minimize the risk of contamination. Stainless steel construction and advanced sanitation systems ensure compliance with strict food safety regulations and standards. By investing in a snack food extruder machine, manufacturers can uphold their commitment to producing safe and hygienic snack foods that meet the expectations of consumers and regulatory authorities alike.
In conclusion, the benefits of choosing a snack food extruder machine are undeniable for manufacturers operating in the snack food industry. From enhanced efficiency and consistent quality to versatility in product development and cost-effectiveness, these machines offer a myriad of advantages that drive success and growth in a competitive market landscape. As consumer demand for diverse and innovative snack foods continues to rise, investing in a high-quality snack food extruder machine is essential for staying ahead of the curve and meeting the evolving needs of discerning consumers.
For inquiries about snack food extruder machine suppliers or further information on snack food production, please don't hesitate to contact us.
Extrusion in food processing consists of forcing soft mixed ingredients through an opening in a perforated plate or die designed to produce the required shape. The extruded food is then cut to a specific size by blades. The machine which forces the mix through the die is an extruder, and the mix is known as the extrudate. The extruder is typically a large, rotating screw tightly fitting within a stationary barrel, at the end of which is the die.
Extrusion enables mass production of food via a continuous, efficient system that ensures uniformity of the final product. These include some pasta, breads (croutons, bread sticks, and flat breads), many breakfast cereals and ready-to-eat snacks, confectionery, pre-made cookie dough, some baby foods, full-fat soy, textured vegetable protein, some beverages, and dry and semi-moist pet foods. Food products manufactured using extrusion usually have a high starch content.
Process
[
edit
]
A non-vacuum short goods pasta extruder fromIn the extrusion process, raw materials are first ground to the correct particle size, usually the consistency of coarse flour. The dry mix is passed through a pre-conditioner, in which other ingredients are added depending on the target product; these may be liquid sugar, fats, dyes, meats or water. Steam is injected to start the cooking process, and the preconditioned mix (extrudate) is then passed through an extruder. The extruder is a large, rotating screw tightly fitting within a stationary barrel, at the end of which is the die.[1] The extruder's rotating screw forces the extrudate towards and through the die. The extrudate is in the extruder for the residence time.[citation needed]
Many extruded products puff and change texture as they are extruded because of the reduction of forces and release of moisture and heat.[1] The extent to which it does so is known as the expansion ratio. The extrudate is cut to the desired length by blades at the output of the extruder, which rotate about the die openings at a specific speed. The product is then cooled and dried, becoming rigid while maintaining porosity.[citation needed]
Cooking takes place within the extruder, where the product produces its own friction and heat due to the pressure generated (10'20 bar). The process can induce both protein denaturation and starch gelatinization under some conditions.
Many food extrusion processes involve a high temperature for a short time.[1] Important factors of the extrusion process are the composition of the extrudate, screw length and rotating speed, barrel temperature and moisture, die shape, and rotating speed of the blades. These are controlled based on the desired product to ensure uniformity of the output.[citation needed]
Moisture is the most important of these factors, and affects the mix viscosity, acting to plasticize the extrudate. Increasing moisture will decrease viscosity, torque, and product temperature, and increase bulk density. This will also reduce the pressure at the die. Most extrusion processes for food processing are carried out at low to intermediate moisture (moisture level below 40%). High-moisture extrusion is known as wet extrusion, but it was not used much before the introduction of twin screw extruders (TSE), which have a more efficient conveying capability. The most important rheological factor in the wet extrusion of high-starch extrudate is temperature.[2]
The amount of salt in the extrudate may determine the colour and texture of some extruded products. The expansion ratio and airiness of the product depend on the salt concentration in the extrudate, possibly as a result of a chemical reaction between the salt and the starches in the extrudate. Colour changes as a result of salt concentration may be caused by "the ability of salt to change the water activity of the extrudate and thus change the rate of browning reactions". Salt is also used to distribute minor ingredients, such as food colours and flavours, after extrusion; these are more evenly distributed over the product's surface after being mixed with salt.[3]
History
[
edit
]
Dry pasta manufacturing line from sThe first extruder was designed to manufacture sausages in the s.[4] Dry pasta and breakfast cereals have been produced by extrusion since the s,[2] and the method has been applied to pet food production since the s (first extruded dog food: Purina Dog Chow in , and first extruded cat food: Purina Friskies in ).[4] Some domestic kitchen appliances such as meat grinders and some types of pasta makers use extrusion. Pastry bags (piping bags), squeezed by hand, operate by extrusion.[citation needed]
Effects
[
edit
]
Extrusion enables mass production of food via a continuous, efficient system that ensures uniformity of the final product. This is achieved by controlling various aspects of the extrusion process. It has also enabled the production of new processed food products and "revolutionized many conventional snack manufacturing processes".[5] The extrusion process results in "chemical reactions that occur within the extruder barrel and at the die".[6] Extrusion has the following effects:[7][8][9]
The material of which an extrusion die is made can affect the final product. Rough bronze dies on pasta extruders produce a rougher surface than smooth stainless steel dies, considered to make more liquid pasta sauces adhere better;[11] pasta made this way is labelled "bronze die" pasta to indicate a premium product.[12]
Front of a die for making elbow macaroni
Back of the same plastic die
Old metal dies for pasta, showing bottom and top of the dies
The effects of "extrusion cooking on nutritional quality are ambiguous",[13] as extrusion may change carbohydrates, dietary fibre, the protein and amino acid profile, vitamins, and mineral content of the extrudate in a manner that is beneficial or harmful.[13]
High-temperature extrusion for a short duration "minimizes losses in vitamins and amino acids".[1] Extrusion enables mass production of some food, and will "denature antinutritional factors",[1] such as destroying toxins or killing microorganisms. It may also improve "protein quality and digestibility",[1] and affects the product's shape, texture, colour, and flavour.[1]
It may also cause the fragmentation of proteins, starches, and non-starch polysaccharides to create "reactive molecules that may form new linkages not found in nature".[6] This includes Maillard reactions which reduce the nutritional value of the proteins.[13] Vitamins with heat lability may be destroyed.[13] As of , little is known about the stability or bioavailability of phytochemicals involved in extrusion.[6] Nutritional quality has been found to improve with moderate conditions (short duration, high moisture, low temperature), whereas a negative effect on nutritional quality of the extrudate occurs with a high temperature (at least 200 °C), low moisture (less than 15%), or improper components in the mix.[13]
A research paper indicates that use of non-traditional cereal flours, such as amaranth, buckwheat or millet, may be used to reduce the glycemic index of breakfast cereals produced by extrusion.[14] The extrudate using these cereal flours exhibits a higher bulk and product density, has a similar expansion ratio, and has "a significant reduction in readily digestible carbohydrates and slowly digestible carbohydrates".[14] A paper states that replacing 5% to 15% of the wheat flour and white flour with dietary fibre in the extrudate breakfast cereal mix significantly reduces "the rate and extent of carbohydrate hydrolysis of the extruded products",[10] which increased the level of slowly digested carbohydrates and reduced the level of quickly digested carbohydrates.[10]
Products
[
edit
]
Extrusion has enabled the production of new processed food products and "revolutionized many conventional snack manufacturing processes".[5]
The various types of food products manufactured by extrusion typically have a high starch content.[1] Directly expanded types include breakfast cereals and corn curls, and are made in high-temperature, low-moisture conditions under high shear. Unexpanded products include pasta, which is produced at intermediate moisture (about 40%) and low temperature. Texturized products include meat analogues, which are made using plant proteins ("textured vegetable protein") and a long die to "impart a fibrous, meat-like structure to the extrudate",[4] and fish paste.[15]
Cheese curls, a directly expanded snack food
Pasta, an unexpanded food
Meat alternative, a texturized food
Some processed cheeses and cheese analogues are also made by extrusion. Processed cheeses extruded with low moisture and temperature "might be better suited for manufacturing using extrusion technology" than those at high moisture or temperature. Lower moisture cheeses are firmer and chewier, and cheddar cheese with low moisture and an extrusion temperature of 80 °C was preferred by subjects in a study to other extruded cheddar cheese produced under different conditions.[16] An extrudate mean residence time of about 100 seconds can produce "processed cheeses or cheese analogues of varying texture (spreadable to sliceable)".[17]
Confectionery made via extrusion includes chewing gum, liquorice, and toffee.[15] Other food products often produced by extrusion include some breads (croutons, bread sticks, and flat breads), various ready-to-eat snacks, pre-made cookie dough, some baby foods, some beverages, and dry and semi-moist pet foods. Specific examples include cheese curls, macaroni, Fig Newtons, jelly beans, sevai, and some french fries.[18]
If you are looking for more details, kindly visit Dog Food Machine.
Extrusion is also used to modify starch and to pellet animal feed.[citation needed]
See also
[
edit
]
References
[
edit
]
Further reading
[
edit
]
In the realm of food processing, efficiency, consistency, and versatility are paramount. Snack food extruder machines have emerged as indispensable tools for manufacturers seeking to meet the ever-growing demand for a wide variety of snack foods. From crunchy chips to savory puffs, these machines offer a multitude of benefits that significantly enhance the production process and the quality of the final product.
One of the primary benefits of choosing a snack food extruder machine is the enhanced efficiency it brings to the production process. These machines are designed to automate the extrusion process, significantly reducing the need for manual labor and streamlining production. With precise control over parameters such as temperature, pressure, and speed, manufacturers can consistently produce large quantities of snack foods in a shorter time frame, increasing overall efficiency and output.
Consistency is key in the food industry, particularly when it comes to snack foods. Snack food Processing Line excel in delivering consistent quality products batch after batch. By maintaining strict control over the extrusion process, these machines ensure uniformity in texture, shape, and flavor, eliminating variations that can compromise the overall quality of the product. Whether it's crispy chips or airy puffs, customers can expect the same great taste and texture every time they indulge in their favorite snack.
Another significant benefit of snack food extruder machines is their versatility in product development. These machines can handle a wide range of ingredients, allowing manufacturers to experiment with different recipes and create an extensive array of snack food varieties. From traditional potato-based snacks to innovative blends of grains and pulses, the possibilities are endless. Additionally, snack food extruder machines can produce snacks in various shapes and sizes, catering to diverse consumer preferences and market trends.
Investing in a snack food extruder machine can prove to be highly cost-effective for manufacturers in the long run. While the initial capital outlay may seem significant, the efficiency and productivity gains achieved with these machines can lead to substantial cost savings over time. Reduced labor costs, increased production output, and minimized waste contribute to improved profitability and competitiveness in the market. Moreover, the versatility of snack food extruder machines allows manufacturers to adapt to changing consumer demands and explore new market opportunities without the need for additional equipment.
Maintaining high standards of food safety and hygiene is non-negotiable in the food industry. Snack food extruder machines are designed with sanitation in mind, featuring easy-to-clean surfaces and components that minimize the risk of contamination. Stainless steel construction and advanced sanitation systems ensure compliance with strict food safety regulations and standards. By investing in a snack food extruder machine, manufacturers can uphold their commitment to producing safe and hygienic snack foods that meet the expectations of consumers and regulatory authorities alike.
In conclusion, the benefits of choosing a snack food extruder machine are undeniable for manufacturers operating in the snack food industry. From enhanced efficiency and consistent quality to versatility in product development and cost-effectiveness, these machines offer a myriad of advantages that drive success and growth in a competitive market landscape. As consumer demand for diverse and innovative snack foods continues to rise, investing in a high-quality snack food extruder machine is essential for staying ahead of the curve and meeting the evolving needs of discerning consumers.
For inquiries about snack food extruder machine suppliers or further information on snack food production, please don't hesitate to contact us.
Are you interested in learning more about dog food machine for sale? Contact us today to secure an expert consultation!