The third Food Extrusion Seminar, organised by Coperion in close collaboration with the German Institute of Food Technologies (DIL), took place in Germany recently. The in-depth seminar attracted 35 guests from all parts of the world. Most of the participants came from the production and product development departments of food companies.
The lectures were augmented by several practical workshops. One of the highlights of the seminar was a demonstration of high moisture extrusion for the processing of plant proteins into meat analogues. The contribution made by representatives of various scientific institutes included a lecture on current food extrusion research and several poster-presentations of their projects and findings.
The experts’ lectures dealt both with the mechanical engineering aspects of extruders and their peripherals and with the technological and processing aspects of food extrusion itself. Having first been familiarised with the basics of extrusion, the participants were then given detailed information on the design configuration and function of a twin-screw extruder using a Coperion ZSK compounder as an example. Gravimetric feeders from Coperion K-Tron and the drying technology featured on the systems manufactured by Vibra Maschinenfabrik Schultheis were also under discussion.
The processing aspects of the individual stages of food extrusion, such as mixing, kneading, emulsifying, degassing and expanding, were explained in detail, as were the product-specific aspects of extruded food products and individual ingredients. The practical part of the seminar took place in Coperion’s Test Lab, where participants could see what they had learned being put into actual practice in trials carried out on two ZSK extruders (a ZSK 27 MEGAvolume PLUS with 27mm diameter screws and a ZSK 43 MEGAvolume with 43mm diameter screws).
The production of high moisture meat analogues was demonstrated on the ZSK 27 MEGAvolume PLUS laboratory extruder equipped with an innovative cooling die, which has been designed especially for the production of meat substitutes from plant protein concentrate. With its low throughput rates and relatively small size, the ZSK 27 Mv PLUS extruder offers optimum scale-up possibilities for food extrusion on a production scale. The ZSK Mv PLUS series optimally combines a large free volume with high screw speeds of up to 1 800rpm and is thus ideal for the extrusion of both meat analogues and conventional food products.
The second extrusion line, consisting of a ZSK 43 Mv, two gravimetric feeders for solids and a liquid metering pump from Coperion K-Tron, demonstrated the production of breakfast cereals. In the course of this demonstration, the participants were shown how the process can be influenced by different extrusion parameters and ingredients. The demonstration program in the Coperion Test Lab was rounded off with a comprehensive display of almost a hundred various extruded product samples from all sectors of the food industry and a tasting session permitting participants to try various high-moisture meat-analogue products for themselves. Participants were also able to put theory into practice in small groups, the set task being the threading of screw elements onto the screw shafts.
