Hydrogen-bond interactions as quantitative descriptors of food structuring mechanisms during cereal-based food processing

The structure and texture of bakery products is largely controlled by biopolymers hydration and structural arrangements as well as their melting transitions (i.e. starch gelatinization, protein denaturation) during processing. Solutes such as sugars, polyols and soluble fibres present in the water phase can strongly influence these processes. Sugars in sweet bakery products like biscuits and cakes exert important functionality in relation to structure and texture as they largely affect starch gelatinization and protein denaturation. Which makes a substantial reduction in sugar difficult to achieve. In bread, the enrichment in fibre is also technologically hampered by the detrimental effects on gluten network. The mechanisms by which sugars, polyols and soluble fibre interact with food biopolymers is not fully understood. In this lecture we demonstrate how the volumetric density of hydrogen bonds can quantitatively describe the melting transition of starch and proteins in water solutions containing different solutes, i.e. sugars, polyols, soluble fibres and mixtures thereof. Taking as example a bread application, we then show how the volumetric density of hydrogen bonds can be used to describe the functionality of different type of soluble fibres. Insights are provided on the influence of the effective number of hydrogen bonding sites of the fibres on gluten structure, dough rheology and thermo-mechanical behaviour during baking. Overall, this lecture shows how key structuring processes during preparation of bakery products can be largely related to physical parameters descriptive of hydrogen bond interactions.