What are the biggest challenges for plant-protein powder producers today and how can they be tackled?

Over the last years there has been intensive focus on improvement of sensorial and texturizing properties of the plant-based protein products, and with significant success. This topic certainly deserves continued attention, especially since new sources of plant-based proteins are being explored, new food applications are being targeted, and consumer expectations are rising. An additional challenge is around sustainability. The energy and water consumption for the full process from a plant to a final consumer product is still very high. The approach from GEA is on the one hand to reduce primary water consumption in the extraction, washing, or diluting steps, as well as to recycle processed water wherever possible. To tackle the energy consumption, GEA has developed innovative heat pump solutions. The GEA AddCool technology can integrate high temperature heat pump technology into the spray drying process to reduce the carbon footprint by up to 50%.

What is key in developing high-quality plant-protein powders?

When a customer is approaching us with a plant-based protein project we will first create understanding about what the customer needs. Many projects will therefore start with questions like: What is your raw material? What are the final product specifications? and What is the final use of the protein? Very often there is a need for a tailor-made solution and therefore we need a close collaboration with our customer. A top-quality product would be of very high purity (with high protein content), with excellent sensorial properties, with a minimal microbial load, and with a functionality that fits various food applications. However, key in all this is finding the right compromise. Once we know the targets, we can make optimal process choices and select the most suitable equipment to reach a certain specified “quality” in alignment with the end-use of the protein powder. Our goal is to design and build a process that can operate in a stable, reliable way to deliver products with the desired properties and quality, batch after batch.

How does a typical production of a plant-based protein powder look like, and which process stages affect what?

A typical production line starts with a wet-separation stage in which we extract the protein from a raw material in a 1- or 2-steps extraction process, followed by acid precipitation and concentration of the extracted protein into a purified protein curd. Extra washing steps can be introduced to increase the protein content even further. This stage affects primarily the protein yield and purity. The next stage is called “feed preparation”, in which the protein curd is diluted, and pH adjusted, before it will be transferred to the “heat treatment” stage. The heat treatment is primarily needed to reduce the microbial load of the product. The heat treatment, however, also affects the protein functionality since proteins are heat sensitive. It is therefore crucial to select a technology that can run stable and does not overheat the product. The goal is either to limit the heat denaturation as much as possible, or to aim for a very controlled heat activation to reach a certain desired functionality. The functional properties that can be affected are for instance solubility in water, viscosity, water holding capacity, and gelation capacity. The next stage is the spray drying of the heat-treated protein liquid. Spray drying encompasses the atomization of the liquid feed inside a spray drying chamber, in a stream of hot air, which allows the droplets to dry. The size of the sprayed droplets has a direct effect on the particle size distribution of the final powder, unless we recycle this fine powder and let it agglomerate with other droplets to make larger particles. The choice of dryer and drying conditions will affect the particle size distribution, and other related powder properties like bulk density, dustiness, dispersibility in water, wetting ability, etc.

Why is testing on pilot scale so important in the process design phase?

We use our test center facilities to verify and confirm the process choices we have made and proof that we have reached the desired final product quality and functionality. At the same time our customers can follow the complete process line from flour intake to extraction and purification, to feed preparation, heat treatment, and drying. We can even do some functionality testing of final dried powder in our lab. As such, a test is providing unique insights into the whole production process, and it is an important part of the knowledge building around protein production. The benefit of our test center is having all the equipment available on a scale that enables us to make representative samples and a test will therefore provide all the necessary data for scale-up in a reliable way. The produced powder samples can be used for testing in applications or even pre-marketing activities.

Which trends do you see? Are there some new source proteins and/or applications being developed for powders?

Besides soy and pea proteins we are seeing increased activities on newer crops, like mung bean, fava bean, chickpea, canola, lupin, etc. And each raw material can open doors to new applications, as the protein functionalities might be very different. We also see trends towards less refined products and valorization of side streams, to address the sustainability issue. In any case, we should not forget that an increased volume of plant-based proteins also implies that there will be an increased availability of fibers, starch, and oil products. At GEA we have the desire to further optimize the complete value chain and investigate how to integrate the process of protein powder production, with texturizing of the proteins, and final formulation in a food application. This will be an important step into increasing the sustainability of plant-based protein powders.

Join Sarah at Summit Americas April 26-27 for more information at her presentation “Influence of Heat Treatment and Spray Drying on Properties of Plant-Based Proteins.” Register here.