Table 4 Regression coefficients of second degree polynomials of five responses

Parameter	Estimate
	Total polyphenol contents	Total flavonoid contents	Maysin contents	DPPH radical scavenging activity	Tyrosinase inhibition
	Intercept	520.251	57.094	-1215.770	-14.501	108.866
X1 1)	57.873	44.744	46.208	0.601	-2.367
X2 2)	13.099	9.467	17.321	0.409	-0.047
X3 3)	32.782	9.918	70.283	2.866	1.898
X1*X1	-0.452	-0.385	-0.274	0.004	0.017
X2*X1	-0.045	-0.020	-0.111	-0.006	0.010
X2*X2	-0.044	-0.052	-0.095	0.000	-0.009
X3*X1	-0.973	-0.234	-0.481	-0.033	0.029
X3*X2	1.613	0.603	-0.758	0.013	-0.086
X3*X3	-3.117	-1.176	-2.052	-0.163	-0.044

Ethanol concentration (%)
Extraction temperature (°C)
Extraction time (h)