Table 3.

Estimated regression coefficients of the second‐order polynomial equations for RSM analysis of total polyphenols and carotenoid extraction (uncoded) from Centella asiatica

Polyphenols terms	Regression coefficients	Probability	Regression p‐value	R 2	Lack of fit
Constant	4.31512	0.000	0.020	78.35%	0.402
Ethanol %	0.0333913	0.001
Temperature (°C)	−0.0891847	0.623
Time (min)	0.00964536	0.256
Ethanol %*Ethanol %	−4.07814E‐04	0.010
Temperature *Temperature (°C)	040.000914520	0.220
Time (min)*Time (min)	−8.95681E‐05‐	0.620
Ethanol %*Temperature (°C)	2.38095E‐06‐	0.995
Ethanol %*Time (min)	2.73810E‐	0.864
Temperature (°C)*Time (min)	050.000208333	0.667
Carotenoids
Constant	−0.299526	0.000	0.017	79.28%	0.523
Ethanol %	0.0427033	0.000
Temperature (°C)	0.0152902	0.448
Time (min)	0.00668319	0.411
Ethanol %*Ethanol %	−3.32569E‐04	0.017
Temperature*Temperature (°C)	−3.57157E‐04	0.584
Time (min)*Time (min)	−1.87499E‐04	0.262
Ethanol %*Temperature (°C)	0.000226190	0.547
Ethanol %*Time (min)	0.000194048	0.310
Temperature (°C)*Time (min)	0.000163889	0.707