Optimization of Extraction Parameters by Using Response Surface Methodology, Purification, and Identification of Anthocyanin Pigments in Melastoma malabathricum Fruit

Table 3

ANOVA for response surface quadratic model.

Source	Coefficient estimate	Sum of squares	df	Mean square	𝐹-value	𝑃-value	Remarks
Acidified methanolic extraction
Model	1114.595	152059.256	9	16895.473	26.906	0.0001	Significant
𝑋1	103.359	85464.893	1	85464.893	136.105	<0.0001
𝑋2	26.475	5607.274	1	5607.274	8.930	0.0203
𝑋3	68.744	37805.617	1	37805.617	60.206	0.0001
𝑋12	−45.922	8435.296	1	8435.296	13.433	0.0080
𝑋13	22.196	1970.579	1	1970.579	3.138	0.1198
𝑋23	9.254	342.543	1	342.543	0.546	0.4842
𝑋1^2	24.728	2574.683	1	2574.683	4.100	0.0825
𝑋2^2	−48.608	9948.234	1	9948.234	15.843	0.0053
𝑋3^2	11.160	524.442	1	524.442	0.835	0.3912
Residual		4395.537	7	627.934
Lack of fit		874.804	3	291.601	0.331	0.8045	Not significant
Pure error		3520.733	4	880.183
Cor total		156454.793	16
Acidified ethanolic extraction
Model	664.170	162047.676	9	18005.297	16.224	0.0007	Significant
𝑋1	118.806	112918.450	1	112918.450	101.747	<0.0001
𝑋2	57.681	26616.436	1	26616.436	23.983	0.0018
𝑋3	31.763	8070.915	1	8070.915	7.272	0.0308
𝑋12	7.237	209.468	1	209.468	0.189	0.6770
𝑋13	−3.966	62.917	1	62.917	0.057	0.8186
𝑋23	−8.071	260.580	1	260.580	0.235	0.6428
𝑋1^2	31.220	4103.958	1	4103.958	3.698	0.0959
𝑋2^2	−11.849	591.175	1	591.175	0.533	0.4892
𝑋3^2	−48.100	9741.404	1	9741.404	8.778	0.0210
Residual		7768.593	7	1109.799
Lack of fit		6069.165	3	2023.055	4.762	0.0829	Not significant
Pure error		1699.428	4	424.857
Cor total		169816.269	16