Fermented foods (FF) are produced by the transformation of the raw material by microorganisms, giving organoleptic and/or conservation properties to the food. Consequently, they are sources of living microorganisms and there is a body of clue that their regular consumption, in particular the ones containing Lactic Acid Bacteria (LAB), is a promoting factor of human health. Moreover, considering the regularity of the consumption, LAB could modulate the oral microbiota (OM) and the oral functions of the host. The composition of the OM has been shown to be related to taste sensitivity (TS) in human. Therefore, a modulation of the OM could modify TS. Despite a certain disparity between studies, some LAB can persist in the oral cavity from several hours to several days with an important inter-individual variability. The factors at the origin of this variability are not fully known but they could include the oral environment properties such as the oral biology and the interactions with the host OM. Our group has recently shown that oral LAB persistence was lower in rats presenting markers of response to oxidative stress in their saliva. This last finding leads to the hypothesis that a pro-oxidative diet could be an antagonistic factor to the persistence of LAB in the oral cavity. The vegetarian diet has been reported to be less oxidative than the omnivorous diet in many studies. Therefore, subjects who adopted a vegetarian diet appear to be appropriate candidates to study LAB oral persistence and activity. The overall objective of the present project is to elucidate the contribution of oral factors and FF consumption habits on oral LAB persistence and activity and on TS in vegetarian versus omnivorous subjects. The PERSIST project involves 3 research units with expertise in sensory sciences, salivary biochemistry, microbiology and metagenomics.

Cleaning and disinfection (C&D) are among the most important hazard control measures in ready-to-eat food plants. However, these procedures require large amounts of water and generate huge volumes of sewage with high loads of cleaning agents and biocides. More sustainable C&D strategies are therefore needed. Several food business operators have already noted the positive effects of adding an air-drying step after C&D to dry surfaces and thus control growth of microorganisms that are not detached from surfaces. However, air drying is applied empirically and no attempts have been made to define optimal air drying conditions, which would increase the efficiency of lethal hydric stress. The purpose of the present interdisciplinary project, which gathers seven partners including three private companies, is to define optimal air drying conditions in terms of lethal impact on bacteria, sustainability of various air-drying techniques and the distribution of relative humidity, temperature and air velocity in a food processing room. The project will assess whether optimal air-drying conditions can promote the use of environmentally friendly C&D products, decrease disinfection frequency — and thus sewage volume and biocide release into the environment, without affecting, and even improving, food safety and occupational health. Fundamental knowledge on the impact of hydric stress on bacterial death, inactivation, resistance, and adaptation will be produced from experiments conducted on a selected pathogenic bacterium or its surrogate. This will be done to better understand the mechanisms involved and to design a tool to detect non-culturable, stress-adapted cells. Models will be constructed to predict: (1) the distribution of relative-humidity, temperature and air velocity in a food processing room; (2) the energy consumption attributable to the control of air humidity according to the drying technique; (3) the persistence potential of the selected pathogenic bacteria. These models, after validation, will be used to determine the most influential factors and recommendations will be issued on how to reach the lowest microbial load on solid surfaces with the lowest environmental impact.

By producing protein-rich seeds without N-fertilizers, legumes can contribute to satisfying the growing demand for plant proteins for human and animal nutrition while reducing environmental impacts. PEAVALUE will target pea (Pisum sativum L.), one of the most important grain legume crops in Europe, which is of increasing interest for the food industry. However, the use of pea proteins is still limited, notably due to imbalanced amino acid composition and insufficient information on their intrinsic characteristics and techno-functional properties (e.g., solubility, emulsifying, gelling and aggregation properties). The PEAVALUE project aims to improve nutritional and functional properties of these pea proteins. To address this challenge, PEAVALUE will bring together three partners addressing key research aspects; on the regulation of seed protein synthesis (IJPB), genetics of nutritional seed quality (AGROECO), and physicochemical and techno-functional properties of pea proteins (PAM). The project is structured in three complementary and interconnected work packages (WP). In WP1, a translational approach between pea and Arabidopsis will increase knowledge on the accumulation of seed-specific proteins. This WP will provide insights into the functional activity of seed-expressed transcription factor genes and their roles in storage protein synthesis, leading to the identification of regulators of protein accumulation in the seed (Task 1.1). Targeted mutations (TILLING) in homologous regulatory genes will be explored in pea to identify allelic variants associated with novel protein profiles (Task 1.2), whose properties will be investigated in WP2 and WP3. WP2 will provide the data framework required to boost the breeding of pea varieties combining protein quantity and nutritional quality. In this WP, the amino acid composition of seeds from TILLING lines (WP1) will be studied, and a panel of 200 pea ecotypes will be mined for seed protein content, protein and amino acid composition (Task 2.1). Correlations between the ratios of 11S/7S globulins, vicilins/convicilins, and protein/amino acid quality indices, will be calculated to identify protein profiles or genotypes with enhanced quality (amino acid balance). These data will be used for Genome Wide Association Studies (GWAS) using a recently enriched SNP-set offering prospects for linking specific alleles or genes to high seed protein value (Task 2.2). WP3 will exploit the genetic variability revealed in WP1 and WP2 to identify protein profiles with improved globulin recovery and techno-functional properties. A standardized procedure (alkaline extraction and isoelectric precipitation) giving high protein recovery from pea flour while minimizing protein denaturation will be used. We will apply alkaline extraction to the panel of 200 pea genotypes used in WP2 with the aim of identifying, by GWAS, allelic variants or genes associated with variations in the extractability of the different globulins, which remains a limiting factor (Task 3.1). Protein isolates will be prepared from 30 genotypes contrasted in protein composition. The intrinsic physicochemical properties of the proteins, including solubility, surfactant capacity, aggregation and gelling ability, will be studied to identify protein profiles with improved and tunable techno-functional properties (Task 3.2). All the data will be (i) registered in a database that will be a reference for the grain legume community and (ii) integrated through correlation studies and multi-factorial analyses to identify protein profiles with improved nutritional and/or techno-functional properties (Task 3.3).

The objectives of the FLUOPATH project are 1) to find new biomarkers (promoeters that induce the expression of genes of interest) coupled to a fluorescent biosensor allowing to acquire new knowledge in bacterial cell physiology related to the impact of technological disturbances inducing stresses. The study will be focused on the growth, survival and virulence of two pathogens in dairy products (milk, diluted cheese and if possible solid cheese) and 2) to use this knowledge combined with the knowledge present in the scientific literature to improve the models for predicting the microbiological risk in dairy products. The pathogens considered will be L. monocytogenes and B. cereus. The matrices considered will be liquid milk as well as model diluted and undiluted cheese (gelified matrix). New models based on the use at the scale of the single cell and the whole population of biomarkers will be developed to predict growth, resistance and virulence (invasive capacity for L. monocytogenes and entry into sporulation and toxin production for B. cereus) to stress while taking into account cellular variability. A precise quantification of the impact of stressful industrial conditions will be carried out on bacterial responses at the cellular level: probability of single cell / whole poulation growth, survival, toxin production, spore formation, invasive capacity. The challenge is to design and validate in food matrices bacterial biomarkers of phenotypes of interest in risk assessment in order to incorporate the intensity of biomarker response into exposure assessment models.

BLAC HP aims at developing a new strategy for stabilization of refrigerated processed meat products by combining high pressure and biopreservation using lactic acid bacteria. This strategy could become an alternative to the addition of preservatives such as nitrites. The chosen target product is nitrite-reduced diced ham. Thanks to the baroresistance of some lactic acid bacteria, the combination is expected to control both vegetative and spore-forming undesirable flora. It will permit to propose low-energy-produced meat products with high organoleptic quality, with a longer shelf life and with fewer preservatives and bacteriostatic ingredients, particularly nitrites. Our project will not only deeply study the mechanism of microbiological stabilization both at the cell and at the ecosystem levels, it also include the downstream aspects of the development: the resulting nutritional, technological and sensory quality of the product throughout its shelf-life. Furthermore, life cycle analysis will permit to objectively compare the environmental impact of the new process with the traditional process through the creation of new indicators. The program is thus built in a multidisciplinary approach that will provide a solid basis for the understanding and the industrial development of the technology.