Interior and surface colour development during wheat grain steaming

Abstract

During the manufacture of breakfast cereals, browning reactions occur when wheat grains are cooked by direct contact with saturated steam at elevated pressure. The development of surface colour during steaming has been quantified, as a function of cook time, steam pressure and salt content, by measuring standard L*, a* and b* colour parameters. Colour reactions have a significant effect on the lightness (L* and blue-yellow (b*) parameters only. The interior pattern of colouration has been recorded by photo-microscopy of sectioned grains. Grains cooked for shorter times generally have a white central region surrounded by darker material. When cooked for longer, the white centres disappear, by..