Table 2.

Analysis of the regression coefficients to the polynomial equation for milling qualities

Coefficients	Head rice yield	Whiteness index	Specific energy consumption
${\beta }_0$	70.50**	52.55**	76.40**
${\beta }_1$	− 2.68**	0.94**	4.06*
${\beta }_2$	0.64	− 0.35	− 11.08**
${\beta }_3$	− 7.40**	2.1**	28.12**
${\beta }_{11}$	0.45	− 0.30	− 3.87*
${\beta }_{22}$	− 0.22	0.16	1.09
${\beta }_{33}$	0.37	− 1.08**	− 3.33*
${\beta }_{12}$	− 0.63	0.21	2.94
${\beta }_{13}$	− 1.53*	− 0.65*	1.68
${\beta }_{23}$	− 0.10	0.41	− 1.80
R 2	0.9582	0.9210	0.9724
SigLack-of-fit	0.4130	0.1249	0.0918

**Extremely significant at p < 0.01; *Significant at p < 0.05