Simultaneous Optimization of Microwave-Assisted Extraction of Phenolic Compounds and Antioxidant Activity of Avocado (Persea americana Mill.) Seeds Using Response Surface Methodology

Table 3

Regression coefficient (β) and analysis of variance (ANOVA) of the predicted second-order polynomial models for phenolic compounds and antioxidant activity.

Factor	Coefficient (β)
	TPC	TFC	DPPH	ABTS
Intercept	83.19	15.04	53.93	67.44
Linear
X1-conc	−1.20	−0.40	−1.61	−2.27
X2-power	8.17	4.40	14.90	11.97
X3-time	5.31	4.60	12.13	11.43
Interaction
X1 X2	−0.3750	−1.16	−0.8075	0.01
X1 X3	2.19	0.48	−1.13	0.47
X2 X3	−2.17	1.06	5.82	−0.34
Quadratic
	−5.55	−4.32	−4.63	−22.82
	−4.37	−3.56	−5.93	−0.80
	−7.46	1.17	0.9999	−7.35
F-value (model)	31.33	61.66	87.93	76.60
F-value (lack of fit)	1.58	7.04	0.74	5.41
R^2	0.9758	0.9875	0.9912	0.9899
Adj-R^2	0.9446	0.9715	0.9800	0.9770
Pred-R^2	0.8086	0.8679	0.9372	0.9255
CV (%)	3.55	9.28	4.83	5.98

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