It is increasingly known that solid and amphiphilic particles (with a certain affinity for both water and oil) can stabilise emulsions, particularly by positioning themselves at the oil/water interface. These emulsions, commonly called "Pickering emulsions", were observed from the beginning of the 20th century and then studied using synthetic particles (functionalized silica, latex, etc.).
Recent developments are now focusing on biobased particles that have undergone the least chemical and physical transformation. In this sense, powders rich in proteins, polyphenols, polysaccharides and their complexes are good candidates. Plant powders, co-products and fibres have been successfully used to stabilise emulsions.
However, stabilisation of dispersed systems by this type of strategy involves several mechanisms that need to be mastered in order to effectively take advantage of them: adsorption of insoluble particles, but also of the soluble fraction of powders, immobilisation of drops by a network of insoluble fibres or by soluble thickeners, etc.
These mechanisms do not have the same effectiveness, preponderance and resistance to variations in temperature and pH and may depend on the nature of the powder, its history and also the formulation parameters. They must be understood and evaluated in order to control the final properties of the formulas, particularly in terms of stability and rheology.
These aspects have been evaluated and are being further developed for more than 40 vegetable powders (from oilseeds, fruits, etc.), depending on the composition of the powders, the formulation levers and the process parameters.