High protein concentrations even in the dry process

What technical challenges do you see in the production of plant-based proteins?

Producing plant-based proteins from raw materials such as wheat, soya, peas, lentils or other pulses is simple in principle. However, demand is increasing and with it the need to scale up the technology – industrial plants are already processing several tonnes per hour in some cases. In addition, the quality requirements are becoming more stringent, because ultimately the aim is to achieve the right flavour and the required texture. To achieve this, the processes must be optimised and adapted to the requirements of the food industry.

What are the special process engineering features of the production of plant proteins?

With the new foods and especially with protein shifting, we mainly work with dehulled goods. These are finely ground in classifier mills, for example. The aim of deagglomeration is to separate the proteins from the starch granules. The product is left in the grinding chamber for a long time so that the cell structure can be broken down finely enough. The protein-rich fraction is then separated from the starch-rich fraction at approx. 16 to 20 µm in a multiple separator. The protein concentrate is then processed in an extruder into patties, for example, or further processed. Alternatively, protein isolates are produced in a wet process.

That sounds like classic mechanical process engineering. What are the special features of protein production?

It's true, it's essentially a classic technology that has only been improved in nuances. For example, the separators are optimised to achieve better selectivity. But compared to the traditional production of animal feed from pulses, completely new qualities and varieties are being defined for human nutrition. There are specific specifications as to how high the protein values should be. And this is where it gets technically exciting: depending on the variety used, up to 70 % protein content can be achieved in dry processes - that is close to isolate. So if we succeed in eliminating the wet process through a suitable combination of specially cultivated raw materials and mechanical process technology and the products also achieve the required properties, then we can save a lot of effort and energy.

What role does sensor technology play in this?

A very important one. We need to gain a better understanding of the relationships between the raw materials used and the end product that can be achieved with the help of technology. And this is only possible with appropriate sensors. Until now, samples have often been taken and analysed in the laboratory - which of course takes far too long for process control and largely forces manufacturers to fly blind. Online sensor technology, e.g. using near infrared, promises a remedy here - however, the boundary conditions are challenging: the pipelines have enormous diameters and fine grinding naturally produces flammable and explosive dusts, which is why explosion protection must also be taken into account. But if we understand the processes with the help of sensor technology, we can ultimately control them in a targeted manner.

We also work together with breeders and farmers so that they can grow what is needed for the new protein products. Those who bring together this expertise from all interfaces create real added value for their customers.