Coperion Ask the Expert

Challenges in Healthy Snacks Extrusion

What challenges do healthy snacks (high-protein, high-fiber, gluten-free) pose to extruders? How can snack manufacturers overcome those challenges?

Nowadays starch-based snacks are often enriched with fibers and proteins. This can have a major impact on the expansion characteristics (size, shape, porosity) in the manufacturing process. If raw materials with high moisture content (like slurries from fresh fruits or vegetables) or raw materials with high fat content (like press cakes) are used, it is a challenge to introduce enough mechanical and thermal energy into the extrusion process.

It is important to have a production plant that is designed to flexibly meet these challenges. For example, the Coperion ZSK Mv PLUS Food Extruder is an ideal system to overcome such issues. In combination with the comprehensive process knowledge, Coperion helps producers to manufacture snacks that meet current market demands.

The Coperion ZSK Mv PLUS Food Extruder technology includes various features that allow it to flexibly react to changing market demands. The addition of steam directly into the extruder’s process section as well as the possibility of high screw speeds, allows the extruder to produce all the necessary energy so that no preconditioner is needed. Intensive degassing possibilities help to get rid of excess moisture so that even raw materials with a high moisture content can be processed.

How is extruder technology impacted snack innovation/new product development? How is extruder technology driving new product innovation and vice versa?

Coperion’s ZSK Food Extruder provides ideal conditions for the extrusion of snacks. The process section of the twin screw extruder consists of several barrels in which the co-rotating screws operate. The closely intermeshing screws with their tight self-wiping profile eliminate stagnant zones over the whole length of the process section.

The modular design of the ZSK Food Extruder and its unusual combination of free screw volume, screw speed, and torque enable this twin screw food extruder series to be individually configured for every challenge in snacks extrusion. The machine set-up is very flexible and allows precise process control. Producers can process nearly any raw material and recipe and achieve constantly high product qualities.

The complete ZSK portfolio includes a wide range of extruder sizes, allowing producers to process any required throughput range from laboratory to production scale. The ZSK Food Extruder is thus suitable both for the development of new recipes and innovations and for the subsequent production of high volumes.

How has equipment design improved to ensure flexibility, speed up changeovers?

Coperion equips the ZSK Food Extruder with numerous features that speed up changeovers of recipes and ingredients. Feed hoppers, degassing domes and atmospheric ventings are equipped with quick-release clamps. In addition, the ZSK Food Extrusion System has a sleek base frame. Manufactured from stainless steel, it includes more smooth surface area for easier accessibility, which significantly reduces system cleaning effort and keeps downtime to a minimum.

The process section itself is self-wiping. Coperion only uses long-lasting materials for screw elements and barrels. This ensures a long service life. In addition, Coperion designs the twin screws of the extruder to allow a process window as big as possible – so that many different products can be produced without the need to change the screw.

The Coperion ZGF Centric Pelletizer is also designed for fast product changes. The change of the die plate is very easy and only requires the removal of 4 screws.

How can snack manufacturers reach high volumes with their extruders and keep them operating optimally, even with healthy snacks?

Coperion’s Food Extruder has an unusual combination of very high free screw volume, screw speeds up to 1,800 min-1 and a specific torque of 11.3 Nm/cm3 that enables the extruder to be individually configured for every snack food application. Especially high feed intake of raw materials with low bulk density, such as flour, starches and proteins.

As previously mentioned, the ZSK Food Extruder reaches very high throughput rates. At the same time, shearing and thermal stress on the raw materials are very low and the product quality is very high. Steam can be directly injected into the process section. This way energy can be introduced into the product very efficiently – a requirement that is particularly important in the production of healthy snacks.

Extrusion of Direct Expanded Products, such as Snacks

Your Contact

  • Uta Kühnen

    Process Engineer for Food Technology at Coperion

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