Table 2. Regression analysis results of relationships between overall color change (
dE
*
) of outer surface of bamboo and UVA radiation time
Treatment
Coating
Regression equation
R
2
Hot-air dried
Uncoated
Coated
dE
*
= –0.0023 ×
t
2
+ 0.3402 ×
t
+ 0.6276
dE
*
= –0.0014 ×
t
2
+ 0.2495 ×
t
+ 0.0080
0.9849
0.9933
Heat-treated
Uncoated
Coated
dE
*
= –0.0016 ×
t
2
+ 0.2802 ×
t
+ 0.5809
dE
*
= –0.0004 ×
t
2
+ 0.1762 ×
t
+ 0.5643
0.9822
0.9733
UVA: ultraviolet A,
t
: UVA radiation time (h).