Food processing by extrusion.

Health and nutrition is the most demanding field in this era and will be in the future as well. Extrusion cooking has advantages over other food processing techniques due to its continuous process and high yield. The food extrusion process ensures the retention of nutrients due to the high temperature and short required residence time of the food in the extruder. The influence of the extrusion process on various food ingredients and the links between them are of constant interest to researchers. The use of extrusion to develop nutritionally balanced or fortified foods makes it necessary to study the nutritional value of extruded products.

Sustainability is an important trend in the food sector, both at the level of nutrition and food production. Sustainability has become a mega trend that affects almost every area of the business world, and the food sector is no exception.

There are many factors driving this trend, but one obvious reason is that consumers are exposed to food related information almost daily, they recognize that their choices have a strong environmental impact and that this is often not a positive thing.

People are looking for a solution to reduce the possible negative impact of their diet on our planet. This growing awareness is forcing the food industry to undergo a major conceptual revolution, shifting from the traditional foods we have been eating for many years to more sustainable foods.

The food industry has started to look for new alternatives and more sustainable ingredients for the production and design of food products. However, direct substitution of conventional ingredients in traditional food products with more sustainable ingredients can have an adverse effect on taste, mouthfeel, aroma and texture.
The use of proteins from more sustainable sources is gaining importance The fundamental question that arises is: how can we produce high-protein food from more sustainable sources, such as plant proteins, algae and even insects?
One method of production is extrusion, which has been used since the 1950s to produce meat analogs from plant proteins and is still being researched for new recipes for meat analogs. but they don't want to give up the characteristics of meat, such as meaty taste and juiciness in the mouth.

Extrusion offers great flexibility in the choice of raw materials and a wide range of food products that can be designed with this system. These aspects make the process very attractive for research as it can offer many solutions for designing more sustainable food products.
The design of sustainable food systems proceeds in three main areas.
The first is the design of meat analogs based on plant proteins, such as wheat, soy, pea or other plant proteins in general. The challenge is to study the mechanisms responsible for the formation of meaty structures.
Another topic concerns the so-called functionalization of alternative proteins through the use of extrusion technology. By functionalization we understand that proteins can gain new or improved properties, such as better solubility, digestibility or texturizing properties, which then allow them to be used in the formulations of traditional food products or innovative food products.

A third, promising alternative area of application is the functionalization and use of by-products of fruit and vegetable processing There are a large number of food by-products, such as apple pomace from apple juice production, carrot pomace from carrot juice production, and even potato skins or pulp from potato production .

These raw materials are very rich in fibers and bioactive substances, which are very valuable. However, these raw materials are not really used because adding these ingredients to food products can adversely affect the texture and mouthfeel of the food.
Thanks to the use of extrusion technology, we can actually change the performance characteristics of these raw materials, allowing them to be used in food recipes, not only to increase the content of fiber and bioactive substances, but also to create specific textures in food products such as bakery products, smoothies and even sausages
Producing protein-based foods is not a big challenge The challenge is to achieve very specific product characteristics when new or different protein sources are used
Each protein has a different molecular structure and therefore different properties, it is not possible to use the same process to produce the same product from different proteins. Therefore, there is a need for a better understanding of these traditional food processes at the mechanistic level.

Take analog extrusion meat production as an example. Here we can produce meat-like textures, but consumers require a very accurate meat flavor profile and mouthfeel to accept a meat substitute. This requires a comprehensive understanding of the process and behavior of these balanced proteins, which allows us to design tailored meat-like structures meat.

Extrusion is one of the few processes that provides great flexibility in the selection of raw materials and process conditions necessary to produce a wide range of food products. In other words, we can produce many different food products on one extruder. be used as a structuring process to give these ingredients a specific textureFor meat analogs, you may need different textures and flavors

Extruders dedicated to food research have technical advantages, such as the fact that they are modular, which allows you to easily change the configuration of the screw to adapt the process conditions to the protein used Have different dosing locations to add ingredients along the extruder barrel, which helps to optimize the final recipe Extruder can adapt to different levels of throughput due to the large range of rotational speeds of the screws. All these features improve the flexibility of the extrusion process, allowing you to create very mild or very difficult processing conditions, depending on the application we are working on.
Another advantage of small twin-screw extruders is the amount of material needed for experimentation, which can vary from a few hundred grams per hour to two kilograms per hour. they are often very pure, which makes them very expensive to obtain in large quantities. This is not a problem when using small food extruders as it allows us to work with very small amounts of raw materials for research scale testing.