Two-step digestion pathways of hydrogels from pea proteins

Digestion pathways of plant proteins are of high relevance to optimize bioavailability and allergenicity profiles of sustainable and vegan food products. Understanding the structural breakdown of solid food presents a particular challenge, due to the complexity to realize a good model system suitable for comprehensive multi-technique characterization under realistic conditions.

We used a microfluidic chip to study the structural evolution during in-vitro digestion of solid gels from pea proteins. The gel structure was probed in-situ combining confocal microscopy, small-angle neutron and X-ray scattering using the same experimental platform. SDS-PAGE analysis was performed on related solution and gel samples subjected to different digestion times.

Combining multiple techniques we reach a multi-scale picture of gel digestion, revealing the breakdown of a more homogeneous gel into more open connected domains with hierarchical internal structures. SDS-PAGE outlines effects of processing on resulting digestion pathways. As central result, we observe a clear two-step digestion process across techniques, switching at about 8-10 min from the initial response to long-term digestion. Overall, the presented methodology holds promise for detailed structural information in future studies aimed at developing new foods with optimized mechanical, nutritional value, and reduced allergenicity.