Claire Berton-Carabin

Claire Berton-Carabin

Research director

Email : claire.berton-carabin[a]inrae.fr
Phone : (33) 2 40 67 50 76
Link ORCID : https://orcid.org/0000-0002-5585-640X
Link HAL : https://cv.hal.science/claire-berton-carabin
LinkedIn : https://www.linkedin.com/in/claire-berton-carabin-27ab3476/
Other: https://www.inrae.fr/actualites/claire-berton-carabin    

CV Claire Berton-Carabin_Apr 2024_EN.pdf

Publication list_Berton-Carabin_2024-04.pdf

Actual position and research subject

Actual position: Research director (senior scientist, DR2) and leader of the Interfaces & Dispersed Systems (ISD) team
Research theme: Our research interests revolve around the interplay between the composition of oil-water interfaces, their structural organization and the physicochemical stability of food emulsions. Our projects are based on a multiscale, multidisciplinary approach, and range from fundamental research, to primary production and characterization of emulsions all the way to ultimate digestion.
Keywords: emulsions, lipids, plant proteins, interfaces, lipid oxidation, microstructure, food systems.

General scientific objectives and approach

The food sector plays a pivotal role in our modern world, as it has a major impact both on the environment and on human health. It is therefore crucial to be able to formulate food systems that are both sustainable (for example, by promoting mildly transformed, plant-based ingredients) and healthy (for example, by increasing the content in omega-3 lipids, which are largely underrepresented in Western diets despite their highly beneficial health effects).
This may sound simple enough, but such strategies are actually difficult to implement because they directly threaten the physicochemical stability of the processed foods (leading to e.g., texture defects, rancidity, etc.). The inherent structural complexity of most food systems makes it a challenge to unravel, and thus control the mechanisms underlying such phenomena. There is therefore a great need to address this challenge, in a context of rapidly evolving trends that aim at meeting the aforementioned sustainability and health-related requirements.
Our research aims at addressing this challenge in an integrated manner, and for this, we work on understanding the structure and physicochemical stability of a generic type of model food system: emulsions, which consist of small lipid droplets dispersed in an aqueous phase, a structure that is ubiquitous in a broad range of foods (dairy products, infant formula, mayonnaise, dressings, nuts, oilseeds, etc.), as well as in non-food systems (cosmetics, pharmaceuticals, paints, etc.).

Structure of food oil-in-water (O/W) emulsions. PUFAs, polyunsaturated fatty acids.

In essence, emulsions are unstable, first because the thermodynamic incompatibility of oil and water confers the system with a propensity towards physical destabilization. To avoid this, emulsifiers are used, which are molecules (proteins, surfactants) or so-called Pickering particles that have affinity for both phases, thus locating at the oil-water interface. Many emulsions are also chemically unstable because they contain labile nutrients, such as omega-3 polyunsaturated fatty acids (PUFAs), which oxidize readily. Such oxidation phenomena not only degrade the nutritional quality of the food, but they also lead to the formation of off-flavours, making the products unacceptable and impairing their shelf-life. The thin interfacial layer separating the oil and water phases has a key role regarding the physical and chemical stability of emulsions, as it is the contact zone between lipids and aqueous reactants. We thus work on extensively characterizing the composition, microstructure and dynamics of the oil-water interface in emulsions, in order to unravel how it is related to the physical and oxidative stability of the systems. In addition to focusing on the mechanisms underlying the formation of emulsions and their subsequent stability over typical storage periods, we also aim to address their ultimate fate, i.e., their behaviour upon in vitro digestion, which is essential for validating the applications of the developed systems.
Our vision for research is based on a multiscale approach, where coupled techniques are used to probe the mechanisms specifically associated with the different scales, which allows for deciphering the systems’ behaviour in a comprehensive and integrated manner. In such an approach, we explore length scales ranging from the molecular level (the nanometre scale) to the macroscopic level (the appearance and texture of the product), combining simplified model systems (e.g., two-dimensional interfaces) and complex ones (e.g., advanced emulsion prototypes). Thereby, proofs of concepts are generated by building systems with a high level of control (i.e., starting from pure materials that are combined together = bottom-up approach), then used to rationally design systems that meet the actual sustainability-health requirements (i.e., with less transformed, more complex materials = top-down approach). Our objective is to control the microstructure of food emulsions and thereby boost the functionality of key ingredients. Our team holds strong expertise in the areas of plant proteins and polyunsaturated lipids’ chemistry and digestibility, which is key to successfully develop new, breakthrough projects.

Approach based on coupling simplified model systems and complex ones, and characterizing these different systems from the nanometric to the macroscopic scale.

Research axes

Smart biobased Pickering particles for dual stabilization of food emulsions
It is essential to promote the use of natural antioxidants to prevent lipid oxidation in emulsions. However, they are often not efficient because they do not locate at the right place, i.e., the oil-water interface where lipid oxidation is initiated. A ground-breaking strategy is to develop biobased Pickering particles containing natural antioxidants, that have a double role: (i) as emulsifiers, to ensure the physical stabilization of the emulsion; and (ii) as antioxidant reservoirs, which will make natural antioxidants reside at the oil-water interface. To design such emulsions, we have worked on both approaches mentioned earlier, starting with a bottom-up approach, where Pickering particles are built from pure ingredients targeted to a specific functionality. After developing this concept and demonstrating its suitability to boost the efficiency of natural lipophilic antioxidant, in the current follow-up projects, this concept is further applied via a top-down route: biobased materials that naturally contain antioxidants (e.g., phenolic-rich extraction co-products) are selected to yield a similar effect, although via a more sustainable, natural route. This research axis is supported by the advanced (oxy)lipidomics expertise and equipment present in our team. Presently, this axis is being developed in the frame of the project VESTA (Région Pays de la Loire and Nantes Métropole) and of the ITN PICKFOOD, in collaboration with Wageningen University & Research (WUR, NL). 

Rational use of plant protein fractions as emulsifiers
Unlocking the potential of plant proteins to stabilize food emulsions is essential, as these ingredients hold a great promise for improving the sustainability of our food supply. However, the conventional processes that are used to obtain plant protein isolates with high purity require large amounts of water and energy, and alter the proteins’ functionalities. Therefore, we need to obtain plant protein fractions using mild transformation, such as dry fractionation, to yield protein-enriched powders through low environmental impact processes. Such fractions are less pure than isolates, and still contain more than just proteins. In particular, our ongoing work has revealed that protein ingredients from various plant sources (pea, lupin, sorghum, faba bean) contain unexpectedly high amounts of various endogenous lipids, which has never been considered in the field so far, yet may largely alter the emulsion stabilizing properties. Although this research line is still very new, we are convinced that this knowledge may revolutionize the highly dynamic field of plant proteins as functional food ingredients. This axis is being developed in the frame of the project VESTA, of a PhD project funded by INRAE & Région Pays de la Loire, of a collaboration with the university of Sao Paulo (Brazil) and of the ANR France 2030 project LetsProSeed.

Digestive fate of new food emulsions stabilized by natural structures
We believe that any progress in food design, albeit driven by technological incentives, has to be related to the ultimate fate of the system, i.e., in the consumer’s gastrointestinal tract. This is why this axis is dedicated to characterizing the behaviour of the emulsions developed in the first two axes, and of their constituents, under in vitro gastrointestinal conditions. This last axis is thus conducted in parallel and in direct interaction with the other two. It is focussed on two main aspects: (i) the digestive fate of the emulsifying ingredients developed herein (i.e., smart Pickering particles, and mildly fractionated plant protein structures); and (ii) the digestibility of the lipids present within the oil droplets. The latter point is particularly important as stabilizing health-promoting PUFAs in food emulsions will only be beneficial if the deployed strategy does not compromise their bioavailability. The expertise in our team, combined with local and national specialized INRAE infrastructures, are essential to screen the systems and conduct in-depth investigations on this matter. This axis is being developed in the frame of the project VESTA, of a PhD project funded by INRAE & Région Pays de la Loire, and of a collaboration with the university of Campinas (Brazil).

Research axes and their organization and interplay.