Contribution des facteurs "procédés" et des "propriétés de surface" des particules dans les mécanismes impliqués dans la granulation de poudres alimentaires – Réactive-Powder

Even if the properties of food products are classically described using bulk parameters, it starts to be recognized that the functional properties of food powders are mainly dependent on the surface composition and surface characteristics of the particles. The mechanisms dependent on the surface energy characteristics of particles could be considered as largely responsible of phenomena (such as reactivity, friction, and adhesion), that are involved in a large number of technological properties of the food powders (e.g. wettability, solubility, granulation, etc…). Understanding the kinetics of contacts between food particles can be considered as a relevant goal for the Powder Engineering scientists and for the food companies. The main objective of the "Réactive-Powder" research project is to investigate the concept of surface reactivity for food powders, when considering the specific context of granulation mechanisms.
Main applications of the project are linked to the agglomeration of food powders, and more in particular the agglomeration of wheat powders for couscous manufacture.
However, it is obvious that the results of the “Reactive-Powder” project will be of great interest in other domains, and different food powders could be considered during the project to extend the results to other products (e.g. dairy powders, functional ingredients, chocolate powders, sugar-based powders, or agrochemicals), and applications (storage, flowability, dispersion, etc…). In addition, the results of the "Réactive-Powder" project could also be considered as relevant to investigate other technologies for agglomeration process (such as fluidized bed technologies).
The originality of the “reactive-Powder” project can be found as a multidisciplinary approach, build from complementary "basic" research fields. This approach is built by the integration of fundamental scientific fields (process engineering, particle engineering, surface physics and chemistry, physico-chemistry) within some "applied" scientific fields (food biochemistry, food technology, functional properties, and food quality), in regards with specific industrial food applications (mainly wheat products).
Chemical engineering approach of granulation processes will be investigated during the "Réactive-Powder" project at three scales that should be linked.
1. Particle scale (cf. Work Package 1 = WP1).
2. Volume of powder and granulation mechanisms scale (cf. Work Package 2 = WP2).
3. Granulation circuit: process scale (cf. Work Package 3 = WP3).
The “Reactive-Powder” project proposes to answer 3 main scientific issues:
(i) To develop specific analytical methods (physico-chemistry and surfaces physics) able to evaluate the surface properties of the food particles and powders.
(ii) To develop a theoretical approach of granulation mechanisms of the food powders, by integrating the contribution of both particle surface properties and process parameters.
(iii) To develop a technological approach of the granulation processes to integrate the relevant results of the theoretical study of the mechanisms, and to initiate re-engineering of unit operations. The technological approach must make it possible to better control the quality of end-products, to improve the performances or to consider the modernization of the equipments in production plants.

The novelty of the research project "Réactive-Powder" is based on the constitution of one scientific task force which is of complementary competences, based on research units which are specialized in powders (EA LSGA and UMR RAPSODEE), in process engineering (UMR LGPEB and UMR GENIAL), and in food processing (UMR STLO and UMR IATE). The scientific animation of the project is designed to integrate the specific competences of each research unit, to decompartmentalize and to favour the interactions between the scientific groups, and thus to allow the integration of the whole of generated knowledge to answer the question. The industrial transfer is directly considered to food powder domains.