Periodic Reporting for period 1 - PlantEmulGel (Emulsions in Plant-based Edible Cellulose Microfibril Gels: Structure, Texture and Stability)
Reporting period: 2018-12-01 to 2020-11-30
This project aims to investigate a new consumer acceptable all plant-based solutions for stabilisation of edible emulsions, whose design is based on the fundamental understanding of the structure-stabilisation-flow properties of cellulose microfibril (MFC)-containing hybrid systems that are naturally found in plant cells. While there is much empirical knowledge about emulsion rheology and stability, the microscopic physical mechanisms that govern emulsion behaviour are still poorly understood, and in this case, for emulsions with a complexity that goes beyond the standard oil/water/surfactant systems. This lack of understanding greatly hampers the rational design of all plant structured emulsion-based products.
By using efficient deagglomeration of the CMF we will control emulsion stability. By combining macroscopic rheology with imaging techniques, we will establish the relation between the macroscopic flow behaviour and stability of the emulsions and the microscopic structure and interactions, and thereby increase our understanding of flowing emulsions beyond the current empirical models. It will help us to move further and provide a special focus on the mouthfeel of all plant structured emulsions. The prediction of mouthfeel texture attributes from rheology is crucial for the food industry to take a more systematic approach towards product design and optimization to meet consumers' preference is for natural, simple, and flexible diets and other plant-focused formulations as closely as possible. The results of the project are translatable to other industries where emulsion formulation is required.
By using efficient deagglomeration of the CMF we will control emulsion stability. By combining macroscopic rheology with imaging techniques, we will establish the relation between the macroscopic flow behaviour and stability of the emulsions and the microscopic structure and interactions, and thereby increase our understanding of flowing emulsions beyond the current empirical models. It will help us to move further and provide a special focus on the mouthfeel of all plant structured emulsions. The prediction of mouthfeel texture attributes from rheology is crucial for the food industry to take a more systematic approach towards product design and optimization to meet consumers' preference is for natural, simple, and flexible diets and other plant-focused formulations as closely as possible. The results of the project are translatable to other industries where emulsion formulation is required.
We designed and stabilized edible plant-based gels by using homogenization technics, in which we dispersed soybean oil at different concentrations (10%-70%) and in the presence and not of surfactant (WP1). We systematically looked at the effect of the different component on the overall stability of the emulsion and on its shear rheology. The microstructure (MFC and dispersed phase) has been investigated with the help of fluorescence confocal microscopy.
To get better insights on fundamental aspect such as the stability of these emulsions towards realistic flows (WP2), we investigated as a first approach, model emulsion undergoing squeezing flow, similarly to what happens during a swallowing process. Our results show that these model o/w emulsions destabilize because of internal rearrangements of droplets (creeping) in addition to the drainage of the continuous phase due to the squeezing motion. These findings allow for a deeper understanding on how to prevent destabilization of more complex emulsions (e.g. MCF emulsions) in realistic situations such as transport of emulsion or human swallowing.
As part of the working package on the mouthfeel prediction of food products (WP3), we initiated our work by considering, in a first step, simple edible power law fluids such as polymer solutions. This system constitutes a first approximation, yet crucial, step towards the rheology of yield stress fluids (emulsion), since
All the results have been reported in internal meetings and internal reports (confidential according to the contract) within the host institute (Unilever R&D). Publishable results have been published in international peer-reviewed journals, as indicated on the online platform.
To get better insights on fundamental aspect such as the stability of these emulsions towards realistic flows (WP2), we investigated as a first approach, model emulsion undergoing squeezing flow, similarly to what happens during a swallowing process. Our results show that these model o/w emulsions destabilize because of internal rearrangements of droplets (creeping) in addition to the drainage of the continuous phase due to the squeezing motion. These findings allow for a deeper understanding on how to prevent destabilization of more complex emulsions (e.g. MCF emulsions) in realistic situations such as transport of emulsion or human swallowing.
As part of the working package on the mouthfeel prediction of food products (WP3), we initiated our work by considering, in a first step, simple edible power law fluids such as polymer solutions. This system constitutes a first approximation, yet crucial, step towards the rheology of yield stress fluids (emulsion), since
All the results have been reported in internal meetings and internal reports (confidential according to the contract) within the host institute (Unilever R&D). Publishable results have been published in international peer-reviewed journals, as indicated on the online platform.
Throughout this project, we formulated new edible, stable plant-based emulsions for which we can vary the rheological/mechanical properties on demand (e.g. by varying the oil concentration, effect of the surfactant). We put into test their stability by investigating their response to realistic flows. One key challenge is to relate the observed macroscopic properties of this new generation of plant-based emulsion to their microscopic structures. We are currently keep investigating this aspect that opens the door for a better understanding of gel emulsion and broad application in food industry.
As part of the "mouthfeel" aspect of such food products, our first findings obtained with thin food products, show that our tongues, just like our eyes and ears, are logarithmic measuring instruments in agreement. These important results might be generic for thicker food product such as MFC emulsion and pave the way for more accurate prediction of mouthfeel characteristics, that will help in the design of future food product and match customers expectations.
As part of the "mouthfeel" aspect of such food products, our first findings obtained with thin food products, show that our tongues, just like our eyes and ears, are logarithmic measuring instruments in agreement. These important results might be generic for thicker food product such as MFC emulsion and pave the way for more accurate prediction of mouthfeel characteristics, that will help in the design of future food product and match customers expectations.