**8. Future trends**

In the last three decades, the development of extruders has advanced greatly. However, technical innovations will be continuously needed for the evolution of new generation extruders and complementary equipments targeting greater efficiency and higher productivity, increasing throughput, easing process control, enabling the production of numerous sophisticated snacks and improving final product quality. Also, it will always be vital to attend consumer requirements, which nowadays are closely related to nutrition and health foods that promote well-being and a positive life style.

Extruders permit the production of many foods of nutritional importance. The ability of extruders to blend diverse ingredients in novel foods can be exploited in the development of functional foods. Traditional snacks or breakfast cereals can be enhanced by the addition of extra fibres or whole grain flour as ingredients during extrusion, transformed into palatable cereal-based products that also promote beneficial physiological effects. Functional ingredients such as soy and botanicals (fruit, vegetables, cereals, etc.) that present high amounts of bioactive compounds can be used in the extrusion process to develop novel products with phytochemicals and other healthful food components. Improved chemical and immunoassay methods will undoubtedly facilitate research in this area. The extrusion process may have value in the formation of resistant starch and modified starch to promote reduced calories in food products. Extruders may also be interesting tools to obtain microencapsulated materials that have the objective of protecting sensitive additives (such as flavours, etc.), increasing their shelf-life and controlling the release of food ingredients at the right place and time. Carbohydrate matrices, such as hydrophobically-modified starches in the glassy state, have good barrier properties and extrusion is a convenient process enabling the encapsulation of flavours in such matrices.

In the future science and technology of the extrusion field, scientists and engineers should focus on the relationship between composition changes and product quality, evaluating and enhancing nutritional, sensory and functional properties of extruded foods.

#### **9. References**


formation of the fibrilar structure from extruded vegetable proteins are not completely

Denaturation during the extrusion process of proteins results in a reduction of protein solubility, favours digestibility and inactivates antinutritional factors. Also, the extrusion of soy protein eliminates and/or reduces the bitter taste and the undesirable aroma and

In the last three decades, the development of extruders has advanced greatly. However, technical innovations will be continuously needed for the evolution of new generation extruders and complementary equipments targeting greater efficiency and higher productivity, increasing throughput, easing process control, enabling the production of numerous sophisticated snacks and improving final product quality. Also, it will always be vital to attend consumer requirements, which nowadays are closely related to nutrition and

Extruders permit the production of many foods of nutritional importance. The ability of extruders to blend diverse ingredients in novel foods can be exploited in the development of functional foods. Traditional snacks or breakfast cereals can be enhanced by the addition of extra fibres or whole grain flour as ingredients during extrusion, transformed into palatable cereal-based products that also promote beneficial physiological effects. Functional ingredients such as soy and botanicals (fruit, vegetables, cereals, etc.) that present high amounts of bioactive compounds can be used in the extrusion process to develop novel products with phytochemicals and other healthful food components. Improved chemical and immunoassay methods will undoubtedly facilitate research in this area. The extrusion process may have value in the formation of resistant starch and modified starch to promote reduced calories in food products. Extruders may also be interesting tools to obtain microencapsulated materials that have the objective of protecting sensitive additives (such as flavours, etc.), increasing their shelf-life and controlling the release of food ingredients at the right place and time. Carbohydrate matrices, such as hydrophobically-modified starches in the glassy state, have good barrier properties and extrusion is a convenient process enabling

In the future science and technology of the extrusion field, scientists and engineers should focus on the relationship between composition changes and product quality, evaluating and

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health foods that promote well-being and a positive life style.

the encapsulation of flavours in such matrices.

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**1. Introduction** 

properties,


**2. Biocomposites** 

**14** 

*Poland* 

Marek Kozlowski

*Wroclaw University of Technology* 

**Lightweight Plastic Materials** 

Lightweight constructions are increasingly used in automotive, aerospace and construction sectors, because using the low density materials allows reducing the structural weight of products. That may result in substantial fuel savings and a lower carbon footprint in transportation and facilitates manipulation of details in the house construction applications. Moreover, the low material density leads to conservation of natural resources, since less


Cellular and hollow structure polymeric materials offer additional advantages resulting

Preference given to low density materials belong to the factors deciding on a success of polypropylene (PP) in the automotive sector. Being lighter than other plastics for 15-20% PP allows substantial fuel savings – it is assumed that a weight reduction in a car body of 100

Polymer composites constitute a broad group of materials, composed of the macromolecular matrix and various fillers. Currently the filler market for plastic composites is dominated by calcium carbonate (40%) and glass fiber (31%) and some other inorganic fillers such as talc, mica and clay. Although the conventional fillers offer property changes in the composites, their high density is not beneficial to fuel savings in automotive applications. Polymer composites with cellulose fillers are growing rapidly, mainly in the construction and automotive industry. The main advantage of such composites is lower density in comparison to that of glass fiber reinforced plastics. In Fig. 1 the density of polypropylene and PP filled with wood flour (WF), without or with of a compatibilizer (PP/WF/comp) has


from their thermal insulating properties, thus allowing additionally energy savings.

material is required for manufacturing consumer goods. In polymer engineering the lightweight solutions include:

kg brings about 0.3-0.5 litres of fuel savings per 100 km.


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