Instrumental color
Instrumental color was measured in a Spectrophotometer CM-
3500d (Konica Minolta Inc., Japan). Purée samples were filled
into a Petri plate taking care to exclude air bubbles, and placed
into the 30mm aperture masks. Reflectance measurements
were made using geometry d/8 (diffuse illumination and 8◦
viewing angle) with the primary illuminant D65. In addition,
Hue (H) angle was calculated (H = tan−1 b∗
a∗ ) as well as the
Chroma (C) (C =
a∗2 + b∗2).
Total color differences (E) were calculated using the equation:
E =
L∗ − L∗
0
2
+
a∗ − a∗
0
2
+
b∗ − b∗
0
2 (1)
where L∗
0, a∗
0, b∗
0 are the control values for control purées (in
order to evaluate changes after processing).
2.