Microwave Drying Modelling of Stevia rebaudiana Leaves Using Artificial Neural Network and Its Effect on Color and Biochemical Attributes

Table 1

Statistical factors of different models fit of moisture ratio for microwave drying of Stevia leaves.

Model	Equation	Power (W)	Estimated coefficients	R^2	Adjusted R-square	χ^2	RMSE
Lewis		180	k = 0.2153	0.9690	0.9689	0.0030	0.0543
		360	k = 0.3848	0.9849	0.9848	0.0014	0.0373
		540	k = 0.7508	0.9974	0.9974	0.0002	0.0143
		720	k = 1.7050	0.9943	0.9943	0.0004	0.0204
		900	k = 2.4763	0.9992	0.9992	0.0001	0.0087
Page		180	k = 0.10952 n = 1.39671	0.9970	0.9969	0.0003	0.0169
		360	k = 0.28767, n = 1.25896	0.9989	0.9989	0.0001	0.0099
		540	k = 0.75908, n = 0.01986	0.9974	0.9974	0.0002	0.0143
		720	k = 1.63719, n = 0.84917	0.9993	0.9993	0.0001	0.0072
		900	k = 2.41135, n = 0.95692	0.9994	0.9994	0.0001	0.0075
Henderson and Pabis		180	k = 0.23591, a = 1.10368	0.9784	0.9784	0.0021	0.0453
		360	k = 0.41505, a = 1.08311	0.9912	0.9911	0.0008	0.0285
		540	k = 0.74052, a = 0.98617	0.9975	0.9975	0.0002	0.0140
		720	k = 1.65553, a = 0.97161	0.9948	0.9948	0.0004	0.0195
		900	k = 2.46346, a = 0.99417	0.9992	0.9991	0.0001	0.0090
Logarithmic		180	k = 1.15943, a = 1.1594, c = −0.0949	0.9878	0.9877	0.0012	0.0341
		360	k = 1.10756, a = 1.1075, c = −0.0458	0.9941	0.9941	0.0005	0.0232
		540	k = 0.99556, a = 0.9955, c = −0.0194	0.9983	0.9983	0.0001	0.0116
		720	k = 0.96565, a = 0.9656, c = −0.01243	0.9955	0.9955	0.0003	0.0181
		900	k = 0.99468, a = 0.9946, c = −0.00071	0.9991	0.9990	0.0001	0.0095
Wang and Singh		180	a = −0.1565, b = 0.0062	0.9944	0.9943	0.0005	0.0231
		360	a = −0.2747, b = 0.0191	0.9905	0.9904	0.0009	0.0295
		540	a = −0.4870, b = 0.058	0.9486	0.9485	0.0041	0.0639
		720	a = −0.8042, b = 0.1480	0.7764	0.7764	0.0164	0.1279
		900	a = −1.25736, b = 0.3622	0.8723	0.8722	0.0124	0.1115

RMSE:  root mean square error.