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

Table 5

Experiment confirmation of predicted value at optimal extraction condition.

Optimal levels	Anthocyanin yield (mg/100 g)
	𝑌predicted	Experimental value			Mean*	Relative error^a (%)
		1	2	3
Acidified methanolic extraction	1345.320	1297.503	1437.774	1303.348	1346.208	0.066
𝑋1 = 60°C
𝑋2 = 120 min
𝑋3 = 0.5 g : 23.1 mL
Acidified ethanolic extraction	869.290	878.355	886.060	878.355	880.923	1.321
𝑋1 = 60°C
𝑋2 = 86.89 min
𝑋3 = 0.5 g : 35 mL

aRelative error (%) = [(experimental value − predicted value)/experimental value] × 100%.
Mean is average value from triplicate of experimental run.