Table 1. Box-Benhken experimental design with the levels for each investigated factor and resultant total anthocyanin content (TAC).

Run number	Temperature/°C (X1)	t/min (X2)	φ(water)/% (X3)	(V(solvent)/m(sample))/(mL/g) (X4)	w(TAC as C3GL)/(mg /g)
1	25	10	60	35	19.04
2	75	10	60	35	16.99
3	25	60	60	35	17.42
4	75	60	60	35	*
5	50	35	30	10	5.02
6	50	35	90	10	9.25
7	50	35	30	60	15.66
8	50	35	90	60	19.62
9	25	35	60	10	7.75
10	75	35	60	10	10.98
11	25	35	60	60	12.07
12	75	35	60	60	15.25
13	50	10	30	35	12.83
14	50	60	30	35	14.77
15	50	10	90	35	18.24
16	50	60	90	35	16.79
17	25	35	30	35	7.99
18	75	35	30	35	11.38
19	25	35	90	35	9.79
20	75	35	90	35	16.20
21	50	10	60	10	10.21
22	50	60	60	10	8.99
23	50	10	60	60	14.64
24	50	60	60	60	16.69
25	50	35	60	35	16.39
26	50	35	60	35	15.23
27	50	35	60	35	18.46
28	50	35	60	35	16.61
29	50	35	60	35	16.17
30	50	35	60	35	16.05
Optimized condition	75	10	90	50.4	19.8**

Run number is not indicative of experimental run order. *Data omitted; **Predicted yield: w(TAC as C3GL)=21.2 mg/g dm