Recent advances in extrusion technologies

EXTRUSION has become one of the most important food processes in the manufacture of pasta, ready-to-eat cereals, snacks, pet foods, and meat analogues. In snacks and pasta, in particular, the variety of raw materials that are mechanically shaped has expanded to include rice, kamut and quinoa, amongst others. Product shapes and textures are constantly being tweaked, so as to allow manufacturers to serve various demographics - from crunchy dinosaurs and dolphins for preschoolers, crisp shells with creamy fillings for on-the-go tweens and teens, to herb-y whole wheat flatbreads for the health conscious.
One feature - flexibility - is common to extrusion systems highlighted here. For many snack and cereal manufacturers, variety requires versatility, and one or more of these technologies may offer the solutions they need to expand their range.

Protein fibration of soy products

Protein fibration creates new profit centres for meat, poultry and seafood by-products, and expands the market for grain and soybean growers. In partnership with R&D companies, Clextral has perfected the technology and chemistry of 'fiberising' raw protein and transferred the process from the laboratory to the processing plant, and offering turnkey production lines for full-scale commercialisation of innovative products. 
HMEC is a two-stage extrusion process: first, the thermo-mechanical processing of proteins in a screw-barrel assembly (mixing and cooking in the extruder), and secondly, protein texturisation or fibration in a long die assembly. During the first stage, the plasticised protein melts at high moisture content (60-80%) and at temperatures above 140°C. At the second, gelling and fibration transforms the protein into wet meat-like products. After exiting the extruder, final flavouring and colouring are added, and the product is shaped as desired. The process ensures optimum food quality as the ingredients are heated to sterilising temperatures during extrusion, ensuring microbiological safety.
Nuggets, patties, portions, slices, cubes, flakes and crumbles can all be created with HMEC.  Formulas range from 50–90% protein, and added ingredients may include animal protein, cornstarch, egg white, dairy protein, fat, vitamins, minerals and salt. Product attribute include: 

? Fibration - sheets or longitudinal
? Surface appearance – smooth, rough, shiny, matte, even or marbled
? Colour – light (chicken or tuna) or dark (beef)
? Texture – consistent, firm, soft or elastic
? Flavour – many delicious combinations are available, including ethnic varieties

Flexibility with twin screw extrusion

An extruding solution tailored to the production of breakfast cereals, food ingredients and pet food launched by Bühler at interpack offers a modular design and lean concept. Working with process pressures up to 150 bar, a maximum specific torque of 11.5 Nm/cm3 and top temperatures of 200°C, the new PRIOtwin extruder is suitable for a wide range of requirements. The system is particularly suited to processes involving large batches and a given product formula.

Functionality, hygiene and safety, and cost efficiency of production are all hallmarks of lean design. The product can be transferred to the extruder without an infeed screw to the extruder, and a customised solution, the PRIOtherm, is designed for processes that do not require lHombre