PhD project title: Steering protein functionality by smart dehydration (# of pos: 14)

Topic background
Within the Dehydration research theme of Wetsus, we focus on efficiency of water removal, and for this specific project we do this also to steer protein functionality. We work on plant-based proteins that are present in various waste streams of the food industry (e.g., washing water of processes for starch and sugar). We will investigate how proteins can effectively be separated or fractionated and thus made into a sustainable alternative source of proteins with tailored functionality. In feeding a growing world population with sufficient and healthy foods, especially proteins play a pivotal role, since their origin, animal or plant, has a huge impact on sustainability. Ideally, proteins are of plant origin as put down in the European Green Deal, and within this project we contribute to this higher target.

Research challenges
Given the low protein concentration present in the previously mentioned streams, effective separation is needed. Thus, different separation technologies that are in line with the industrial partners in the project will be explored, and compared based on their water removal efficiency. The big challenge will be to do so while keeping the functionality of the protein intact. For dairy proteins, it is known that the processes used for their isolation greatly determine their technological functionality (related to the degree of unfolding of the molecules). Therefore, this project focusses not only on separation, but also on the functional characterisation of the obtained fractions, and isolates. Until now, nobody has been able to link separation processes to protein functionality. If this would become available, this would imply that healthy food design would be speeded up greatly.

Objectives and methodology
The aim of the project is todevelop separation technology to tailor the technical functionality of proteins, and develop microfluidic tools to investigate this functionality. This will be investigated via the two (low temperature) dehydration technologies currently present in the Dehydration theme: Eutectic Freeze Crystallisation (Cool Separations) and Super Critical CO2  (Feyecon). Both are well suited for food products containing heat-sensitive proteins. Besides, also membrane filtration will be considered as an alternative. Proteins play a key role in emulsification, i.e. they prevent coalescence of e.g. oil droplets coated with the particular protein and with that phase separation. For protein functionality measurements, we will use a combination of tailor-made microfluidic technology and high speed camera imaging to monitor how well the proteins are able to stabilize small oil droplets.