Utility of CIE tristimulus system in measuring the objective crumb color of high-fiber toast bread formulation

The major objectives of this study were to develop high-fiber toast bread formulations with lighter crumb color and to evaluate the CIE tristimulus system to measure the color of crumb as affected by the addition of various flour mill fractions. The optimized straight-dough bread making method (AACC method 10-10B) was used for conducting the baking trials. CIE L* a* b* values of the crumb were measured. Additional color attributes, (whiteness value, redness index (RI), saturation index (SI) and total color difference (Delta E), were calculated from these L* a* b* values. Compared with flour samples, the germ and bran fractions had significantly lower CIE L* a* b* and whiteness values, but higher redness and saturation indices, indicating darker color and hue for the latter. Test bread samples having up to 30% bran and 10% germ, were lighter in crumb color than the control whole wheat flour bread. It was concluded that high-fiber toast bread, with lighter crumb color than whole wheat flour bread, can be produced by using white flour, and equal proportions of coarse and fine bran at 20%, germ at 5%, and sodium stearoyl-2-lactylate at 0.5% levels. The CIE L*a* b* tristimulus system can effectively be utilized for distinguishing crumb color variations in toast bread samples.