dr.ir. LMC (Leonard) Sagis

dr.ir. LMC (Leonard) Sagis

Associate professor


  • 1990 MSc Chemical Engineering TU Eindhoven
  • 1994 PhD Chemical Engineering Texas A&M University


Research Interface Dominated Materials

The aim of my work is to develop novel multiphase systems, such as emulsions, foam, or encapsulation systems, and to characterize the link between the microstructure of these multiphase systems and their macroscopic properties (for example their rheology, fracture behavior, or release of functional ingredients). A major part of my investigations focus on the dynamic behavior of the interfaces in these systems, and the effect of this behavior on behavior on a macroscopic scale. 

The structure-function relationships established in this work are used to develop novel functional food products, such as foods with encapsulated healthy ingredients (vitamins, omega 3 fatty acids, peptides, probiotics), highly stable emulsions and foam. For the synthesis of these microstructured systems we rely heavily on self-assembly processes and enzymatic synthesis routes. 

The motivation to focus on interfacial properties is based on the fact that emulsions or encapsulation systems tend to have very high surface to volume ratios, and their macroscopic behavior is therefore often dominated by the interfacial properties. For this reason these materials can be considered Interface Dominated Materials (IDMs). For a targeted design of IDMs with specific functional properties, a detailed understanding of the surface properties (surface tension, bending rigidity, surface rheological parameters, permeability), their relation to structural properties on molecular scales, and their relation to macroscopic behavior, is absolutely essential. 

The focus of much of our recent work is on exploring the functionality of plant-based protein extracts, to contribute to the Protein Transition. Plant proteins have a far more complex behavior than the dairy- or meat-based proteins they are intended to replace. They tend to perform worse with respect to foaming and emulsifying behavior, and sourcing for functional plant-based protein ingredients with resource-efficient and sustainable production methods remains a big challenge. During extraction and processing the structure of plant proteins is often significantly affected, leading to a further decrease in nutritional and functional properties. A wide range of physical, chemical and biological (e.g. fermentation) methods have been applied in an attempt to improve functionality. New plant-based products are entering the market continuously, but their development is mostly based on trial-and-error approaches, and a consistent approach to go from starting materials to products, which is robust with respect to source variations, is still missing. We are using multidisciplinary multiscale approach, for a range of pulses and seeds, to establish the generic link between structure and functionality for these proteins and identify the optimal processing and modification methods. This knowledge can lead to a more targeted and faster design of new plant-based products, with optimized nutritional, functional, and sustainability attributes.