High-protein food products produced by extrusion

High-protein foods have gained popularity among consumers as a way to consume nutrient-dense foods. Consumers are looking for ways to increase the amount of protein in their diet. Thus, there is a need for new high-protein food products to meet the growing consumer demand for protein. The flexible development of products based on textured vegetable proteins requires the creation of vegetable products with meat-like textures.

Zamak Mercator laboratory extruders for extruding food are perfect for conducting research on the extrusion of vegetable proteins horizontal cylinders allow quick access to their interior for process control or (and) cleaning Top and side ports allow for dispensing liquids and other additives The use of stainless and acid-resistant steel ensures an appropriate level of cleanliness High torque of the screws ensure the ability to process products that present high resistance and extend the possibilities of handling The equipment necessary to conduct research on food is a modular cooling matrix in combination with a laboratory extruder Zamak Mercator is an ideal tool for the production of textured vegetable proteins on a laboratory scale.

The modular design of the die enables the extrusion of products of various sizes as well as different raw materials such as wheat gluten or soybeans. Conducting product tests in laboratories or pilot plants provides time savings, greater flexibility and lower costs compared to the situation when testing should be carried out on production equipment.
The laboratory extruder provides full control over the entire process. ½” UNF measuring ports installed in the die allow you to measure the pressure or temperature of the processed material. Thanks to accurate measurements, structural changes in the product can be recorded in real time and correlated with the obtained product properties.
The modular design of the die consisting of the lower and upper halves ensures the possibility of extruding products of various sizesWe are happy to adapt the die to your requirements
Stay one step ahead of your competition by utilizing a lab extruder and modular cooling die in the development of meat-like plant protein products.

Laboratory extruders for extruding food

Laboratory extruders are small versions of production extruders. However, there are many differences between Laboratory and production extruders. Laboratory extruders are more extensively equipped with functions that allow testing many materials, which makes them very versatile devices. They have functionalities that facilitate and accelerate the research process. Laboratory extruders are equipped with a rich set of precise measuring sensors.
• Laboratory extruders are ideal for short delivery and response times for low volume batches or pilot trials. They can be adapted to all applications.
• Designed to enable efficient new product development and testing of new extrusion processes can be critical to a manufacturing company or research lab Lab extruders can be used to reduce time to market for new products.
• Laboratory food extruders can test new food ingredients. Different formulations can be tested to find out how they behave during extrusion. The amount of extruded samples is usually sufficient to be easily made for testing and evaluation of a newly developed product.
• Continuous research and development ensures continuous improvement and optimization of final products. Final products require quality control. This is most easily done on a laboratory scale.
• Universal laboratory extruders designed for small batches of product, with the possibility of a quick change of the research process, can be effectively used in the training process.They allow you to use your time effectively and maximize the effectiveness of training. Laboratory extruders are ideal devices for practical acquisition of new knowledge and experience.

Scalability from labs to food production

Laboratory extruders are a valuable research and development tool for performing research that will eventually be scaled up to production. In addition to preventing the use of valuable production resources, significant material cost savings can be achieved by making small batches of product. The key to scale-up is the flexibility of the laboratory extruder. The versatile laboratory extruder allows you to test and modify processes for best results before scaling.
Another factor for successful scaling is ensuring that the material has exactly the same experience in the production equipment as in the lab extrusion lines Zamak Mercator Lab Extruders are fully customizable and can be equipped with specialized process control instrumentation to continuously measure and record parameters the exact mapping of the processThe technical parameters of these extruders are highCompact and versatile, and at the same time stable and precise, Zamak Mercator laboratory extruders turn out to be a very profitable investment in equipment intended for research.
Factors affecting food extrusion
Food extruding equipment has a very long history and meat extruders were used to produce sausages as far back as the 1870s Dry pasta and breakfast cereals were massively extruded in the 1930s and many bakeries also started using extruders for food production Since then food extrusion technology has crept in for everyday kitchen appliances such as herb and coffee grinders, meat grinders and pasta machines.
The beneficial properties of the food extrusion process lead to consistent and repeatable quality, uniformity and efficiency in the mass production of food products. Food can be profiled into cooked or cold-formed products or semi-finished products of any size, color, shape and consistency.
Starchy foods extrude well, such as pasta, breads, cereals, snacks and candy The food extruder mixes the ingredients evenly, utilizing the heat generated by the friction of the process, as well as additional heating during cooking, before passing the material through the die to form the product final.
Reactions and changes in the state of the food material in the extruder plasticizing system and at the die face contribute to different food processing results Some foods, such as cereals and snack chips, are formed using rapid expansion or swelling that occurs when the material is released by the matrix into the environment.
Custom-made extrusion dies can impart additional properties to the final product, for example, a long die gives vegetable protein the fibrous appearance of real meat, or bronze casting gives pasta a rougher surface for better sauce retention.
As with any extrusion process, the determining factors are material composition and flow properties, screw speed, barrel length, temperature, pressure, humidity, die shape and product cutting speed, all of which must be closely monitored and controlled to ensure that the final food product has required features of appearance, touch and taste.
Most extruder food production takes place at fairly low humidity levels, i.e. below 40%, as moisture reduces the viscosity of the mix and plasticizes the processed material. The increased density of the wet mix lowers the torque and lowers the die pressure.Wet extrusion requires feeding and mixing in a twin screw extruder and requires better process temperature control.
Another factor affecting the texture of the final products is the salt content, which affects the product's aeration and consequent expansion after extrusion Salt also affects the color of the food as the resulting water absorption affects the browning ability of the material However, it is a useful carrier that helps distribute colors evenly and flavors throughout the product.

Extrusion technology of textured meat analogs

Moisture-controlled extrusion process can be used to create plant-based meat and seafood textures During extrusion, proteins are subjected to thermal and mechanical stress by heating the cylinder and shearing the screws As a result, the structure of the protein changes, leading to the formation of soluble and/or insoluble aggregates Long segmented matrix A chiller attached to the end of the extruder allows the proteins to align in the direction of flow through the die, creating an anisotropic network of proteins.
A wide range of end product properties can be achieved by changing the process conditions during moisture controlled extrusion processing Process conditions in the screw section can be changed using independent process parameters such as barrel temperature, screw speed and their configuration when using segmented screws Process conditions in the die section can be changed through the cooling rate and die geometry This greatly improves process flexibility Extrusion is a complex process with many variables and the sections are directly connected Any change in one section (e.g. cooling rate in the die section) changes the process conditions in the other section (e.g. pressure and filling degree) auger section).
Conducting research allows a better understanding of the effect of temperature and/or moisture content on the molecular structure and physicochemical and final product properties in the case of soybean and pea proteins. In addition, thermal and mechanical treatment during extrusion processing affects the molecular structure of proteins and properties.
Extrusion of textured proteins is one of the many successful applications of this unique cooking process Formed meat analogues are blends of various protein sources such as protein isolates, glutens, albuminsExtrusion cooked vegetable and other proteins are blended with oils, flavors and binders before being formed into sheets, patties, strips or discs.
Extruders are able to produce a meat analog that has a remarkable similarity in appearance, texture and mouthfeel to meat The use of extrusion cooking in the food industry has shown that extrusion equipment can produce a wide variety of products Some of these products include breakfast cereals, breadcrumbs, snacks , instant rice, instant noodles, starch modifications, animal feed.
In addition to changing the texture and restructuring of plant food proteins, the extrusion system performs several other important functions: denatures proteins Proteins are effectively denatured during the moist, thermal extrusion process Protein denaturation lowers solubility, destroys biological activity of enzymes and toxic proteins Deactivates residual growth inhibitors native to many plant proteins in raw or partially processed Growth inhibitors have been shown to have adverse physiological effects on humans or animals as shown by growth or metabolism studies Controls raw or bitter flavors commonly associated with many plant-based sources of dietary protein.Many of these undesirable flavors are volatile and are eliminated by extrusion and decompression of the protein at the extruder head.

Description of the extrusion process

Food extrusion can be defined as the process of mixing, homogenizing and shaping food materials with relatively low moisture content, and in recent times food materials with high moisture content.
Food extrusion is a modern high-temperature cooking process with the ability to apply pressure in the process, which can be generated by the screws of the extruder. The extrusion process can be accompanied by additional operations and such as conveying, kneading, heating, cooling, mixing and forming in one device Food extrusion is widely used in the processes of research and production of food for humans and animals.
The extrusion process typically involves applying a large amount of energy to the food ingredients under pressure and in a short time to produce a continuous viscous dough.
Extruder cooking has basically revolutionized the food industry, as it has obvious advantages over conventional food processes. High-temperature operation time is a matter of seconds, which has a beneficial effect on maintaining the properties of ingredients and active substances while ensuring high quality parameters.
High process temperatures and pressure increase the rate of destruction of harmful microorganisms, enabling the production of end products with a long shelf life due to their low final moisture content in the process Continuous extruder cooking process has economic advantages due to the replacement of multiple batch processes with a single process Final content can be controlled moisture, thus avoiding the need to evaporate a large amount of water.

Division of extruders into single-screw and twin-screw

Textured proteins can be processed in single and twin screw extruders There are differences between the two designs Single screw extruders are machines that have produced and continue to produce the world's largest tonnage of textured soy protein products For textured proteins, the limiting factor in the use of single screw extruders is the ability to use a narrow range of raw materials Their use requires good uniform ingredients.
The plasticizing system of the twin-screw extruder consists of two cooperating, interlocking, self-cleaning sets of screws. The screws are divided into segments, thanks to which their arrangement can be modified, thus affecting the processing properties of the extruder to a large extent. more positive product pick-up characteristics compared to a single auger As a result, the twin auger design allows for a greater variety of product processing.
Generally speaking, food extruders can be divided into single screw and twin screw extruders. Raw materials with high coefficient of friction, such as corn grits, rice cones, whole grains, extrude well in single screw extruders.For this reason, they are widely used to extrude snacks and breakfast cereals.
Twin screw extruders are classified as co-rotating and counter-rotating depending on the relative motion of the extruder screws relative to each other.
Co-rotating twin-screw extruders offer better conveying, mixing than single-screw extruders. Compared to a counter-rotating twin-screw extruder, a co-rotating extruder can run at much higher rotational speeds, thus providing higher throughput and better mixing.
The die is a key element in the design of the extruderThe die area is the section of the extruder that occurs after the food material leaves the extruder barrelThe die is usually made up of three parts, which are the transition, distribution and die plate sections When the dough leaves the die, the temperature and pressure drop rapidly and the product it expands when released into the environment.

Food extruder flow modeling

The modeling of food extruders mainly depends on the development of plastic extrusion, but it is important to appreciate the similarities and differences in food materials.
Plastics are more homogeneous in nature, which can be characterized chemically and physically. On the other hand, food extrusion uses different food ingredients. These materials are starch or protein biopolymers that differ from plastics by prior processing, thus the extrusion process causes extensive changes in the chemical and physical nature of extruded foodModelling in food extrusion is a much more complex process than plastic extrusion.
Until recently, very few papers have been published on the mechanism of material flow and energy transfer in an intertwined co-rotating food extruder Mainly due to the complexity of the geometry and flow behavior Most of the papers reported treat the material flow in a twin screw extruder as similar to a single screw extruder
It is critical to be able to predict the effect of processing and material parameters on product temperature due to the sensitivity of food raw materials to over- or under-treatment Improper heat treatment of food materials can result in poor nutritional value with unacceptable organoleptic properties Knowledge of the heat exchange encountered in food extrusion is essential to scale up and design of food extruders and temperature control systems.
Modeling heat transfer in a food extruder
It is very important to be able to predict the effect of processing and material parameters on product temperature due to the hypersensitivity of the food raw material to over- or under-treatment.
There are many studies related to the effects of process parameters on extrusion efficiency. Research conclusions can be very diverse and sometimes even misleading. With almost the same process conditions, the results obtained are completely different and inconsistent. The reasons for these discrepancies may be differences in experimental conditions, types and conditions of the extruder used, techniques measurement and the equipment used.Other reasons may be the instability of the tested parameter values, the way of analyzing the result and the purpose of the study, which imposes restrictions on the level of required experimental accuracy.
Nor is there a standardized experimental procedure and method of analysis for food extrusion technology that is available for other conventional food processing techniques, so each study tends to use a method suited to its own specific condition. effective cylinder heating and cooling systemsThese systems should ensure the maintenance of the set temperature in the food processing process.

Extruder die and product expansion

The die is one of the main components of the extruder configuration The die allows the extruded dough to expand rapidly into various shapes and sizes depending on the configuration of the die section Understanding the material properties and flow pattern of the extruder die is fundamental in controlling extruder performance, shape and product quality.
It has been observed that the die entry pressure drop for a viscoelastic fluid is much greater than the entry pressure for a Newtonian fluid of nearly the same viscosity. The inlet pressure drop of the extruder dies increases with the decrease of the extruder barrel diameter ratio. die These factors are very important in the design of dies for food extruders.
Process conditions combined with die parameters can have a significant impact on extrusion quality The die diameter and length play a very important role in the extrusion process The flow rate decreases proportionally as the length of the die is increased Typically when cooking with extrusion, reducing the size of the die opening increases the pressure in the die The role of the die in defining texture in extruded products is often overlooked and underestimated The shape of the die will affect the shape and texture of the finished item Tapered die opening will create a smoother surface of the product and cause less mechanical damage to the extruded ingredients A die insert with a sudden change in cross-section and short length will cause more mechanical damage to food ingredients and a finer cellular structureThe shear environment of laminar flow through the matrix influences the textureHigher shear rate matrices have the potential to influence the texture more The product's high shear rate in the matrix causes more shear damage and reduces molecular size, creating softer products with smaller pores, increased solubility and lower mechanical strength. The matrix can also greatly affect textured soy protein.

Conclusion

Food extrusion is a technology that will continue to receive research and application attention in developed and developing countries There is no standardized experimental procedure and analysis method for food extrusion technology available for other conventional food processing technologies Studies on the mechanical and rheological properties of food dough are needed There is a need for basic research on food properties, similar to plastic extrusion, where the properties of plastics and the melting point of plastics are well known. Studying the properties of food dough will help to obtain information and data for research and development purposes.The area of co-extrusion of cereal products with additives is very promising The improvement in processing offered by extrusion cooking will improve the nutritional quality of these products and provide value-added food to the population This is a potential source of huge economic benefits and research opportunities
The current trend towards vegan and vegetarian diets is driving the use of plant-based proteins as meat and seafood substitutesWhile most meat substitutes are still based on soy or wheat gluten protein, new meat analogues with alternative proteins, binders, flavor enhancers and natural colors are also emergingNew research Research and development will need to address and address the interaction of flavors and colors with plant proteins, and how water binds to plant proteins to enable new plant-based meat and seafood analogues to increase juiciness and freshness.

Professional research twin screw extruders you can rely on

Zamak Mercator is a manufacturer of twin-screw research extruders with screw diameters of 2 x 12/2 x16/2 x 20/2 x 24 mm, co-rotating and counter-rotating, with a range of L/D up to 48, with a modular and non-modular structure. The construction of the extruders is based on innovative design assumptions, modern components and is based on many years of experience gained in the plastics processing industry.

Due to the high complexity of the extrusion process, the research extruder should have all the capabilities of industrial extruders and even exceed them.

Our research extruders are reliable and repeatableThe preparation time for subsequent tests is shortIn the practice of a research laboratory, meeting such an assumption means that in a short time the extruder must reach and stabilize the working parameters set by the scientist Changes of the set parameters must be reliable, repeatable and fast All measurement data must be reliable.

The first key factor determining the quality and credibility of research on the extrusion process is the control and reliable measurement of temperature in each zone of the extruder.

Ensuring a reliable measurement and ensuring a stable and consistent with the set values of the melt temperature inside the extruder barrel is not an easy and cheap task to implement.

The following requirements must be met in total:

The cylinder of a research extruder is divided along the longitudinal axis, often with multiple ports for side feeders and ports in the top of the cylinder, e.g. for dispensing liquids or gases.

The heaters are arranged in such a way that the heat is evenly distributed in each heating and cooling zone.

Temperature sensors are positioned to provide reliable measurement and limit thermal interference from heaters operating at a higher temperature than the plasticizing system.

To avoid uncontrolled temperature rises, each zone of the cylinder is equipped with an efficient and fast cooling system that works in conjunction with the heating system.

The whole is controlled by a precise multi-zone temperature controller.The control system has the ability to calibrate and shape the heating and cooling characteristics of the plasticizing system by the researcher.

The second important factor is the technical parameters and the ability to adapt the device to research on various materials.

The basic technical parameters are:

Maximum torque per worm, maximum revolutions, drive motor power and maximum operating temperature.

The technical parameters of twin-screw extruders enable operation with virtually all available materials, provided that the material from which the screw and cylinder is made allows it.

We designed cylinders with exchangeable inserts constituting the working surface of the cylinder. In practice, this means that we can adapt the extruder to work with other materials in a short time, moreover, exchangeable inserts allow for quick and relatively cheap regeneration of the plasticizing system. In principle, inserts can be made of any material and technology, which is suitable for this purpose. A set of augers is easy to replace with another one.
Virtually all materials can be researched, spanning the medical, pharmaceutical and food industries

The Vertex II geared extruder replaces two extruders, extending your research capabilities.

Our extruders are equipped with torque dividing gears that can work as co-rotating and counter-rotating, the change of the direction of rotation is made automatically from the operator's panel. This unique feature allows us to test such materials in full.

Zamak Mercator research extruders can be equipped with a precise tensometric measurement of the force acting on the screws lengthwise, this mechanism additionally extends the possibilities of conducting research.

You can get reliable scale-up, reduced time-to-market Our twin-screw extruders offer flexible configurations from small batches to pilot scale or low-volume production and are ideal for research and development in the polymer, pharmaceutical, biology and nanotechnology sectorsPharmaceutical manufacturers need precise and reliable twin-screw extruders you can rely on to create new material blendsOur instruments meet a wide range of process requirements, even with the most challenging formulations.