Speaker
Description
Plant cell wall polysaccharides play a key role in determining the structure, mechanical properties and digestibility of plant-based and alternative foods. However, their hierarchical organization in complex hydrated matrices remains challenging to resolve using conventional techniques. Small angle neutron scattering (SANS), especially when combined with X-ray scattering and complementary tools such as microscopy and rheology, provides unique insights into the nanoscale organization of polysaccharides.
Here, we present a series of studies using SANS to unravel the multi-scale structure of cell wall polysaccharides in both model and complex food matrices. In composite cellulose hydrogels containing major plant cell wall polysaccharides, SANS revealed distinct interaction mechanisms, including their co-crystallization with cellulose microfibrils and surface adsorption. In agar-based hydrogels, combined SAXS/SANS enabled the identification of double-helix aggregation and bundle formation as the structural basis of gelation, linking molecular organization to macroscopic rheological properties. This structural framework was then applied to a complex system: the edible seaweed Porphyra and its structural evolution during in vitro gastrointestinal digestion. The results revealed the presence of gel-like polysaccharide networks protecting seaweed cells, which limited enzyme accessibility and protein release during the gastric phase, but were disrupted after the intestinal phase, resulting in a relatively high protein digestibility.
These studies highlight the potential of neutron scattering to support the rational design of sustainable food materials with tailored functionality and digestibility.