[Thesis defence] 02/02/24, Thomas Breniere: "Impact of genotype-practice interactions on the content and sequestration of carotenoids in plant matrices and on the associated health effects. - Case study of two Solanaceae species".

Title of the thesis

Impact of genotype-practice interactions on the content and sequestration of carotenoids in plant matrices and associated health effects. - Case study of two Solanaceae species

Date and place

Oral defense scheduled on Friday 02 February 2024 at 2pm
Venue: Amphitéâtre ADA CERI 339 chemin des Meinajaries Avignon, 84000 France
Room: Amphitéâtre ADA

Discipline

AGRONOMIC SCIENCES

Laboratory

UPR 4278 - Laboratory of Experimental Cardiovascular Physiology

Framing

• Mrs NADIA BERTIN
• Mrs CATHERINE RIVA

Composition of the jury

• Ms Nadia BERTIN INRAE Thesis supervisor
• Jean-François LANDRIER INRAE / INSERM / AMU Thesis co-supervisor
• Ms Catherine RIVA Avignon University Thesis co-supervisor
• Ms Christine MORAND INRAE Rapporteur
• Mr Yves DESJARDINS Université Laval, Quebec Rapporteur
• Mr Philippe OBERT Avignon University Examiner
• Mr Emmanuel GEOFFRIAU Institut Agro Rennes - Angers Examiner
• Ms Anne-Laure FANCIULLINO IRHS Thesis co-supervisor

Summary of the thesis

The health effects of fruit and vegetables are partly due to their richness in phytomicroconstituents such as carotenoids. The aim of this thesis was to use an interdisciplinary approach to analyse the relationship between growing conditions, carotenoid sequestration and the health value of fruit. The health value of fruit was assessed at various levels: I) the microconstituent composition of mature fruit; II) the bioaccessibility of carotenoids in an in vitro digestion model; III) the metabolic phenotype in a model of induced obesity in male C57BL/6JRj mice supplemented with fruit powder for 12 weeks; IV) the vascular function of hyperglycaemic male Wistar rats previously force-fed fruit with high antioxidant capacity. To do this, two fruits described as accumulating massive amounts of carotenoids were grown: tomato (Solanum lycopersicum, six 'industrial tomato' genotypes, H1311, M82, IL2-5, IL54, IL6-2 and IL12-4) and goji berry (Lycium barbarum, cultivar FPW07). The fruits were produced in a controlled greenhouse environment under two water regimes: a control 'Control Irrigation' (CI) regime with complete restoration of evapotranspiration, and a stressed 'Deficit Irrigation' (DI) regime, for which we halved the irrigation volumes from anthesis to harvest compared with the CI regime. We hypothesised that water deficit and/or post-harvest treatments (steaming, drying, etc.) could modulate the health value of the fruit by affecting its macro- and micro-constituent composition, the cellular properties of the matrices and the bioaccessibility of carotenoids. The results of this research show that in an in vitro digestion model, DI reduces the overall bioaccessibility of carotenoids. In vivo, the results suggest that consumption of tomato or goji berry may be associated with positive health effects in a metabolic and vascular context, with the effects largely dependent on genotype and post-harvest treatment, but little on water deficit. This work suggests that genotype and/or post-harvest treatment are major levers for improving the health value of fruit throughout the production chain.

Keywords : health value,carotenoids,bioaccessibility,tomato,goji,water deficit