Maltodextrin promotes calcium caseinate fibre formation through air inclusion

Abstract Commercial calcium caseinate is available as spray-dried and roller-dried powder. Shearing a dense spray-dried calcium caseinate dispersion gives rise to a fibrous material, whereas shearing dense roller-dried calcium caseinate yields a layered material with only slight anisotropy in mechanical strength. The addition of a polysaccharide phase in a continuous protein phase may lead to formation of fibrous structures after shearing, which is hypothesized to be a result of the elongation and orientation of the dispersed polysaccharide domains. We report the effect of the addition of maltodextrin to roller-dried calcium caseinate on structure formation. The strength of the material increased with the addition of maltodextrin, which is partly caused by the withdrawal of water from the caseinate phase towards the maltodextrin phase, leading to a higher local caseinate concentration. The anisotropy of fracture stress and fracture strain were enhanced with up to 5 wt% maltodextrin. The effect of maltodextrin on the mechanical anisotropy and fibrous appearance could be ascribed to the greater air incorporation as a result of the presence of maltodextrin.