Research and projects
My research is focussed around the relationship between biophysical properties of proteins and polysaccharides, and their structural attributes within the context of behaviour during digestion in the gastrointestinal tract, and in particular with regards what makes some foods, like peanut, more allergenic than others, and why some food proteins become allergens. Different types of foods may elicit a variety of physiological and psychological responses which will have a direct impact on our health and well being. We are discovering what the rules are that govern the changes in natural and fabricated food structures (including nano-scale structures) during digestion and how that affects the form and uptake of food proteins, including allergens, by the gut epithelium. A bioinformatic analysis of food allergens of plant and animal origin has shown a restricted membership of protein superfamilies, supporting molecular and structural approaches to allergen classification. We are now seeking to discover why certain protein scaffolds dominate known allergens from foods, how the structural and biological properties conferred by these scaffolds may predisposes a protein to becoming a food allergen, and how this may be altered by food processing and the food matrix. In particular we have been investigating how thermal denaturation and adsorption at interfaces results in formation of partially-folded states and aggregated protein networks. The impact of such changes, together with biomolecular interactions with other components, such as lipids, on the kinetics of simulated gastrointestinal proteolysis is being investigated using proteomic approaches. This is complimented by studies on the effect on allergenicity, in terms of, for example human allergic IgE-binding capacity, undertaken in collaboration with researchers around the world through the EuroPrevall project. A second strand of research activity has been the characterisation of polysaccharides as a function of genetics and environment using a combination of spectroscopic imaging techniques (Fourier-transform infrared and Raman spectroscopies) coupled with analysis using mass spectrometry (protein constituents) and NMR spectroscopy (cell wall components). Through BBSRC and EU funding in collaboration with researchers at the Institute of Food Research and Rothamsted Research, we have shown, for the first time, spatial heterogeneity in the distribution of non-starch polysaccharides with different branching patterns (and hence solubility). This alters during grain development in hitherto unsuspected ways and we have now demonstrated that the structure of the walls alters in response to the GI tract environment, which may have implications for understanding the role of whole grain foods in human health.