R&D applications for aquafeed extrudates: Laboratory scale testing to determine appropriateness for species and sustainability
by Brabender, Germany
Gluten-free flatbread, omega-3 noodles, chocolate rice, lupine puffs, woodruff licorice, vegan hot dogs? Extruder products are some of the most trendsetting and promising options for product innovations on the market.
There is practically no other process that offers so much potential for entirely reshaping a food matrix. Therefore, practical equipment with extrusion devices are now necessary tools for product developers in the baked goods, pasta, and snack industries.
With the TwinLab-F 20/40, Brabender has now introduced its current top model for the R&D laboratory world. We spoke about the background, possible uses, and innovative device features with the application technicians in Brabender's extrusion laboratory, Julian Foerster and Michael Landers.
Extruded foods — Where is the trend headed?
ML: With extrusion as a modern key technology, new developments for snack products, breakfast cereals, flatbreads, noodle products or confectionery can be prepared at lab scale. Innovative foods are made possible by varying the parameters of screw speed, temperature, and shear during their interaction at extrusion.
JF: At the moment, for example, protein texturisation of plant-based raw materials for the booming market of meat substitute products is in high demand. Laminar structures are created in the product during the wet extrusion with subsequent cooling of the denatured proteins. This meat-like texturing provides sufficient bite and the desired mouthfeel.
Which current challenges from the industry need to be solved in the laboratory?
ML: We need to be able to evaluate the options for the product development process step-by-step in a realistic fashion in the laboratory. For this purpose, we offer our clients technical solutions.
This is because any possible risks of new procedures must be checked out reliably before proceeding to production with them in large quantities. This means that we need recipes and real products, for example, for the sensory test, texture analysis, or color value optimisation during development. The TwinLab opens up a wide field in this regard: Raw materials can be extruded in various geometries in sophisticated process conditions.
Market-driven solutions with new raw materials and innovative products — Where does lab scale extrusion come in?
JF: Our TwinLab has been designed primarily for research and development. It enables contemporary and flexible product design from a range of raw materials: Not just "classic" corn, wheat, rice, or soy, but also with other legumes such as peas, lentils, or lupines.
Above all, this also includes innovative products made of potatoes, vegetables, or nuts in the snacks segment. Raw material mixtures with fibers, oils, sugar, or micronutrients are also possible.
ML: For this purpose, the TwinLab has six openings for dosing solid or liquid ingredients, four on the top and two on the side of the liner. I would like to name a few typical examples of the practically unlimited applications: Hot extrusion for direct or indirect expansion, such as for snack foods or breakfast cereals, cold extrusion for pasta, and wet extrusion for textured products.
Various die geometries enable almost an unlimited variety of imaginative shapes: The default is the round die head, which can be configured to diameters from one-to-seven millimetres with die inserts. The TwinLab produces expanded flatbread, confectionery, or snacks with the ribbon die head. And the tubing die head even makes macaroni...
What can the new TwinLab extruder do?
JF: The range of applications focuses mainly on recipe and product development. In addition, it can also be used to create samples for quality control or for the optimisation of production processes. The new TwinLab is a twin screw extruder at lab scale.
We have used it to test a wide range of shapes, colors, and flavors. During development, it was important to us to be able to adhere to realistic processing conditions. This saves on costs, is consistently quality-oriented, and ongoing production is not impacted for our clients.
ML: Along the length of the liner, four heating and cooling zones provide optimisable temperatures in every process area. With screw speeds of up to 1200 rotations-per-minute, it offers users great flexibility with regard to specific mechanical energy (SME). The twin screws can be individually configured with conveying, kneading, and mixing elements depending on the process sequence. This allows for a wide range of product simulations with different shear forces and allows the TwinLab to be used for a wide range of purposes. With a width of 60 centimeters, it also fits in even the narrowest of laboratories.
Where do you see the application-related advantages for product development?
ML: Well, I could go on for hours about that. But I'll name four main arguments for practice-oriented product development with laboratory extruders such as the TwinLab instead of experiments which interfere with production.
For one, you can vary your application ideas in a wide variety of ways with regard to raw material, formulation, machine, and product. Secondly, you have the option of establishing methods for measuring your quality parameters from the raw material to the end product in advance.
Thirdly, you require significantly less time for your tests, save on material, and have almost no product wastage. Last but not least: You do not need to worry that your ongoing quality management system will be impacted in the first place.
JF: Universities and other research institutions are also increasingly involved in such practice-oriented product development. In collaborative projects with the sciences and businesses, we at Brabender support our clients with extrusion technology know-how.
Smart workflows are the talk of the town at the moment — does this apply in the laboratory as well?
JF: Yes, we can offer our clients huge advantages with the Brabender product family in this respect. The TwinLab is controlled via our MetaBridge software. It allows multiple laboratory devices to be networked — for evaluating, exchanging, and linking measurement data. Off the top of my head, I have two examples: The Moisture Tester MT-CA is used to measure the moisture level, first in the raw material and then the extrudate, as an important parameter for expansion and shelf life.
The degradation of starch in extruded products made of flour is a key product characteristic that can be analysed easily and quickly in the ViscoQuick.
ML: And there are two additional technical aspects for laboratory staff: The process unit is separated horizontally and can be folded up vertically — a feature that only a few models on the market offer.
This not only allows for the visual evaluation of individual processing steps, but also allows for convenient screw removal and fast cleaning. Furthermore, in addition to various alarm and safety features for operation, the TwinLab also fulfills the highest hygiene requirements according to EU Regulation 1935/2004 — not entirely unimportant in this day and age.
So is lab scale extrusion worth it as a building block for a corporate future strategy for baked goods and snacks?
ML: Product development at lab scale is an essential path to innovative food assortments. We offer our clients suitable technical equipment for lab scale extrusion, the advantages of which are clear: Economical use of resources, speed and flexibility on the path to the pilot product, and quality-assured production. This allows a return on investment to easily be realised with the corresponding innovation philosophy in the company.
JF: New and ongoing development of products is indispensable, both grain-based and using alternative raw materials. The food industry and consumers wish to have interesting products — preferably with added value in terms of taste and health.
We at Brabender believe that extrusion as a technical application will play a key role for new consumer goods. That is why we are glad to invite clients to have a look at the TwinLab on site in our customer and technology center in Duisburg — and not just look, but also experience it in operation live and with their own materials!