Grant: Discovery Grants Program - Individual

The objective of this program is to elucidate the molecular interactions between plant dietary fibers and polyphenols, and measure their impact on the biological properties of cereal, fruit and vegetable-based food systems.Non-digestible polysaccharides (NDPS), also known as dietary fibers, and (poly)phenolic compounds (PPC), are two classes of bioactive nutrients concurrently found in foods such as cereals, fruits and vegetables. NDPS and PPC can interact at the molecular level under processing and digestive conditions. However, the fundamental drivers of these interactions, their effect on NDPS's biophysical and PPC's biochemical properties, as well as their impact on nutrients absorption are largely unknown. This proposal builds upon intriguing and exciting preliminary data on oats and orange fruits. We showed that with oats and gums, the extent of binding of PPC onto NDPS was highly dependent on PPC's structure and that such binding could either increase or decrease NDPS's viscosity proportionally to amount of bound PPC. Importantly, these observations made in solution remained valid in oat bran through in vitro digestion. On orange fruit, data showed that binding of NDPS and PPC increased PPC's digestive stability but decreased PPC's ability to reduce intestinal glucose absorption in vitro.We therefore hypothesize that non-covalent interactions between NDPS and PPC can modulate their respective biophysical and biochemical properties in food systems and through the gastro-intestinal tract, and could be manipulated to influence advantageously biological effects or processing outcomes. To test this hypothesis, we will use model NDPS and PPC representative of cereals, fruits and vegetables, selected for their distinct structural features and will specifically: 1- Systematically characterize the molecular interactions of model NDPS and PPC as a function of their structures; 2- Evaluate the impact of NDPS-PPC complexation on NDPS's biophysical properties; 3- Evaluate the impact of NDPS-PPC complexation on PPC's biochemical properties; 4- Determine the impact of NDPS-PPC complexation on the availability of glucose from food.Through an interdisciplinary and collaborative approach of research and HQP training (two PhD students and five undergraduate students over five years), this program will improve the understanding of the fundamental drivers of NDPS-PPC binding and its biological impact. Along with our preliminary observations, the anticipated outcome of this research program could influence the way cereals, fruits and vegetables are bred, grown, transformed, formulated and consumed. This knowledge will have broad agronomy, food processing, biotechnology and nutritional implications and could be used to design functional food systems with benefits to Canadians consumers and Canada's agri-food sector.