Table 3.

The coefficients of the coded terms significant at p < 0.05 in the quadratic imperial model indicating the effect of PUAE process parameters on each response extraction.

	Yield (g/g)	TPC (mg GAE/g DW)	TFC (mg QE/g DW)	AOX (mg GAE/g DW)	TAC (mg Cyn-3-glc eq/100 g DW)	BI
Intercept	0.45	148.97	31.93	137.27	22.94	42.44
x1- S/S Ratio (g/100 mL)	−0.031	−10.76	−3.32	−10.62	−0.31**	−10.02
x2- Power (W)	0.018	11.53	2.53	8.80	1.70	−4.78
x3-Duty cycle (%)	0.022	14.00	2.81	8.57	1.49	−5.22
x4- Time (min.)	0.021	19.68	4.79	11.75	3.79	−5.68
x1x2	−1.683E-003**	−2.84*	−0.051**	−0.81**	−0.15**	0.94**
x1x3	−1.832E-003**	−1.22**	0.31*	6.37	0.12**	0.86**
x1x4	0.012	−2.44**	0.92	3.54	−0.15**	3.75
x2x3	−0.020	−10.61	−1.44	−10.10	−1.39	−2.01
x2x4	−0.013	0.38**	−0.21**	−0.51**	−0.50	−3.06
x3x4	7.998E-004**	6.93	0.42	1.98*	−0.98	−3.58
x1x1 (x12)	0.025	15.75	0.96	14.33	−0.62**	8.21
x2x2 (x22)	−0.025	−11.42	−2.63	−5.56*	−1.58	6.30
x3x3 (x32)	−0.016	−6.44*	−1.52	1.18**	−1.49	−3.75*
x4x4 (x42)	−0.052	−21.50	−3.19	−5.37*	−1.79	−2.66**

TPC: total phenolics content, TFC: total flavonoids content, AOX: antioxidant capacity TAC: total anthocyanin content, and BI: browning index, x₁, x₂, x₃ and x₄ denotes the dimensionless coded values of peel solid to solvent ratio (g/100 mL), power (W), duty cycle (%), time (min), not significant; **p > 0.10; *0.05 < p < 0.1