Determination of Curcuma longa L. (Turmeric) Leaf Extraction Conditions Using Response Surface Methodology to Optimize Extraction Yield and Antioxidant Content

Table 1

Central composite design matrix of two test variables in coded values and observed responses from 11 extraction conditions for the extraction of turmeric leaves.

Run order	Type	Temperature, X1 (°C)	Time, X2 (min)	Yield, Y1 (%)
1	Factorial	40.000	60.000	12.4
2	Factorial	100.000	60.000	15.6
3	Factorial	40.000	240.000	15.0
4	Factorial	100.000	240.000	15.2
5	Star	40.000	150.000	14.3
6	Star	100.000	150.000	16.1
7	Star	70.000	60.000	14.0
8	Star	70.000	240.000	15.4
9	Center	70.000	150.000	15.0
10	Center	70.000	150.000	15.2
11	Center	70.000	150.000	15.0