Formation and properties of viscoelastic masses made from kafirin by a process of simple coacervation from solution in glacial acetic acid using water

•Kafirin viscoelastic masses can be formed by coacervation from glacial acetic acid.•Viscoelastic mass formation was achieved by rapid addition of water with low shear.•Viscoelastic masses could be formed from kafirins differing in their subclasses.•Glacial acetic acid greatly increased kafirin α-helical conformation.•Viscoelastic masses maintained their functional properties when stored at 10 °C.

Stable viscoelastic masses have been formed from kafirin in a mainly aqueous system. Kafirin was dissolved in glacial acetic acid (GAA) and simple coacervation was performed by rapid addition of 15 °C water under low shear. Kafirin precipitated out as a network of hydrated fibrils which could be hand-kneaded into a viscoelastic mass. These could be formed from a very wide range of kafirins, including those where β- or γ-subclass expression was suppressed. Kafirin composition influenced the appearance of the masses but did not fundamentally affect stress-relaxation behaviour. Fresh kafirin masses exhibited similar elasticity and viscous flow balance to gluten. They maintained functionality when stored for several days at 10 °C but their elastic component increased. FTIR showed that when kafirin was dissolved in GAA its α-helical conformation increased substantially. Dissociation of the kafirin molecules in GAA, assuming a α-helical conformation may have enhanced water binding, enabling viscoelastic mass formation.