Two-step digestion pathways of hydrogels from pea proteins

Abstract

HYPOTHESIS: 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.EXPERIMENTS: 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.FINDINGS: 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