The reflective surface colour of breads was measured on crumb, using a Σ80 Colour Measuring System (Nippon Denshoku Inc., Tokyo, Japan), and L, a and b values were recorded. The L value represents lightness component on the surface, and the value ranges from 0 to 100 for darkness to whiteness, while a and b values are chromatic components of redness (+) to greenness (−) and blueness (+) to yellowness (−), respectively. Each type of bread sample was individually measured in triplicate. Whiteness index (WI) was calculated on the basis of the following equation