PhD position OT-22104

Potential of fermentation in reducing allergenicity of lupin protein-based foods

35000 Rennes et 44000 Nantes

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INRAE presentation

The French National Research Institute for Agriculture, Food, and Environment (INRAE) is a major player in research and innovation. It is a community of 12,000 people with 272 research, experimental research, and support units located in 18 regional centres throughout France. Internationally, INRAE is among the top research organisations in the agricultural and food sciences, plant and animal sciences, as well as in ecology and environmental science. It is the world’s leading research organisation specialising in agriculture, food and the environment. INRAE’s goal is to be a key player in the transitions necessary to address major global challenges. Faced with a growing world population, climate change, resource scarcity, and declining biodiversity, the Institute has a major role to play in building solutions and supporting the necessary acceleration of agricultural, food and environmental transitions.

Work environment, missions and activities

You will be welcomed in two INRAE units UMR STLO and UR BIA

The Science and Technology of Milk and Egg joint unit of INRAE and Institut Agro Rennes (UMR STLO) has a strong background in 4 scientific fields: Biochemistry, Processing, Microbiology, and Nutrition. UMR STLO explores the mechanisms and issues involved in the transformation of milk, eggs, and vegetables, using multidisciplinary and multiscale approaches, from the native molecules to their final functionality or digestibility. Moreover, UMR STLO has a longstanding experience with the digestion of animal and plant proteins using in vitro static, semi-dynamic, and dynamic digestion and has been at the forefront of the harmonization of in vitro digestion protocols across Europe (INFOGEST). Our research aims In-depth characterization of native compounds (casein micelles, identification of egg white proteins…) and their potential bioactivity, as well as the behaviour of various molecules from milk, eggs, and vegetables during processing including their structural modification and digestibility. Auto- and hetero-assembly of proteins and mechanisms underlying their innovative applications. Protein & Lipid Physico-Chemistry: Microstructure, ripening of milk and/or vegetable fermented products and safety. Bacterial biodiversity: Exploration, mechanisms involved, fermentative and probiotic properties and added value by fermentation of milk and other raw materials (e.g., mixed vegetable-milk). Main missions are to develop public expertise on milk and egg components, to enhance the quality and safety of fermented dairy products and egg products and preserve their biodiversity, to train Master's and PhD students and promote their integration, and to enable society and industry to benefit from new advances, particularly in the bacteria involved in fermented dairy product processing. The Microbiology team is particularly interested in the molecular mechanisms behind the organoleptic, sanitary and probiotic quality of fermented foods and will host the PhD student.

The Biopolymers Interactions Assemblages (BIA) INRAE unit has oriented its research project towards the sustainable transformation of agricultural resources and plant biomass. It notably aims to answer questions about the construction of a healthy and quality diet for specific populations, the preservation of the environment through the appearance of new sources of protein, and the consideration of the food-health link via the understanding of the digestive deconstruction of food and the occurrence of food allergies. The Allergy team of UR BIA has a strong background in the evaluation of the potential allergenicity of novel food protein sources, such as pea (industrial collaboration) colza, and hemp, and the impact of food processing on allergenicity and will host the PhD student. More specifically, a recent study from our team has revealed the potential of gluten fermentation by Lc. lactis LLGKC18 to reduce gluten allergenicity (El Mecherfi et al., 2021). Furthermore, the team routinely uses immunochemical methods, in vitro methods of the intestinal barrier, and in vivo methods to evaluate allergenic potential and the prevention of food allergy. The BIA unit also disposes of a state-of-the-art LC-MS/MS and an in-house animal facility to perform in vivo models.

To meet the global challenges of the overall dietary transition, we need to diversify our protein sources by increasing the proportion of plant-based foods and notably legumes in our diet. However, this transition raises new issues. While lupins have undeniable nutritional advantages, some of their main proteins are known allergens. Allergy to lupins is fairly rare, but there exists a cross-reactivity between peanut and lupin proteins. Fermentation of plant-based products improves their preservation, as well as their organoleptic and nutritional properties, but is also of great potential for the reduction of protein allergenicity. The aim of this thesis project is to gain insight into the ability of lactic and propionic acid bacteria to reduce the allergenicity of lupin proteins. Lactic acid and propionic acid bacteria strains will be screened for their ability to hydrolyse lupin proteins, with a particular focus on allergenic epitopes. They will also be screened for their immunomodulatory properties on immune cells. Their impact on the immunoreactivity of lupin proteins will be studied. Lupin-based fermented products will be developed, and the benefits of this fermentation will be assessed in the context of food allergy. The impact of fermentation, and then of digestion, of fermented products on the allergenicity of lupin proteins will be addressed. This work will open up new avenues in the field of innovative and functional fermented foods, in a context of increasing incidence of atopic diseases.

Objective:

 The aim of this thesis project is to gain knowledge on the ability of lactic and propionic acid bacteria to reduce the allergenicity of lupin proteins.

 The main key steps of the thesis are:

- To screen lactic acid and propionic acid bacteria strains for their proteolytic potential towards lupin proteins, with a particular interest in allergenic epitopes, including those of conglutins.

- To screen lactic acid and propionic acid bacteria strains for their immunomodulatory properties in vitro on immune cells. 

- To assess in vitro the impact of strains on the immunoreactivity of lupin proteins. To evaluate whether the presence of other proteins modifies the immunoreactivity of lupin proteins.

- To identify and quantify known lupin allergens.

- To formulate products based on lupin proteins, fermented by strains selected on the basis of proteolysis, immunoreactivity and immunomodulation criteria. To assess the impact of fermentation on the immunoreactivity of lupin proteins, alone or in mixtures with dairy proteins, in vitro. The fermented products will be characterised from a sensory point of view, in partnership.

- To evaluate the impact of fermentation and digestion of fermented products on the allergenicity of lupin proteins using in vitro cell models.

Special conditions of activity: This thesis project is funded by the French National Research Agency (ANR) as part of the France 2030 programme, "Developing plant proteins and diversifying protein sources - Legume proteins - Wave 2". It is part of the PULSAR project, " Protein Utilization and production in Lupinus: Species Association-driven Reviving of an orphan legume species", coordinated by Joëlle Fustec from the ESA in Angers.

This thesis project involves two INRAE research laboratories, the UMR INRAE-Institut Agro, Science et Technologie du Lait et de l'Œuf (STLO) in Rennes and the UR INRAE, Bioprocédés Interactions Assemblages (BIA) in Nantes. The research work will take place half of the time at STLO and half at BIA.

It will moreover be in collaboration with the GRAPPE team at the ESA in Angers for sensory analyses.

Collaborations

As this project is an integral part of the PULSAR project, the PhD student will take part in the various meetings related to the project and will present the progress of his/her work. This will be an opportunity to interact with the project's academic and private sector partners.

Training and skills

Master's degree/Engineering degree

Recommended training: A candidate's initial training in biology (microbiology/chemistry/biochemistry) will be necessary to successfully complete this project.

Knowledge required: proficiency in office automation tools (Word, Excel, Powerpoint or freeware versions) and bibliographic analysis is essential. Sufficient knowledge of English is required for reading and writing publications, as well as for oral scientific communication.

Appreciated experience: Knowledge of immunology would be appreciated.

Skills sought: The candidate should have the ability to summarise, organise and reason analytically, as well as to work and interact with various colleagues in different research environments, in two different sites.

INRAE's life quality

By joining our teams, you benefit from (depending on the type of contract and its duration):

- up to 30 days of annual leave + 15 days "Reduction of Working Time" (for a full time);
parenting support: CESU childcare, leisure services;
- skills development systems: trainingcareer advise;
social support: advice and listening, social assistance and loans;
holiday and leisure services: holiday vouchers, accommodation at preferential rates;
sports and cultural activities;
- collective catering.

How to apply

I send my CV and my motivation letter

Offer reference

  • Contract: PhD position
  • Duration: 36 months
  • Beginning: 01/11/2024
  • Remuneration: 2100 euros gross per month
  • Reference: OT-22104
  • Deadline: 30/06/2024
Centre Brittany-Normandy

UMR STLO - Rennes et UR BIA - Nantes 35000 Rennes et 44000 Nantes Website

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