Sample color was evaluated using a Color Flex spectrocolorimeter
(Hunter Associates Laboratory Inc., Reston, VA, USA) and reported as
L*, a* and b* values, in which L* is a measure of lightness, a* represents
the chromatic scale from green to red and b* represents the chromatic
scale from blue to yellow [21]. The sample was filled in a 64 mm glass
sample cup with three readings in the same place and triplicate determinations
were taken per sample. The white tile and black glass were
used to standardize the equipment.