2.4. Colour measurement
The reflective surface colour of breads was measured on crumb,
using a R80 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