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Novel gels from wheat gluten proteins
Wheat storage gluten proteins are among the most complex proteins families comprising at least fifty different proteins, with extremely broad polymorphisms. Wheat gluten proteins are moreover largely insoluble in water, rendering their study difficult. Gluten proteins are responsible for the remarkable viscoelastic properties of dough. However despite extensive studies over more than 200 years, in order to provide structural and mechanistic basis for the improvement of the viscoelastic properties of dough and of the quality of resulting food products, there is still a crucial need to understand supramolecular organization of gluten proteins.
We have proposed a novel extraction protocol that allows for the first time careful structural and rheological analysis of gluten protein suspensions over a wide range of protein concentrations. Our system appears therefore as a unique model system to investigate the supramolecular organization of gluten proteins and its impact on the viscoelastic properties of gluten gels.
Rheological measurements show a spontaneous and very slow and concentration-dependent gelation of the samples which can be rationalized using percolation models. Consistently, scattering data highlight a hierarchical structure strikingly similar to that of polymeric gels, thus providing some factual knowledge to rationalize the viscoelastic properties of wheat gluten and their assemblies.