Optimization Conditions of Ultrasound-Assisted Extraction for Phenolic Compounds and Antioxidant Activity from Rubus alceifolius Poir Leaves
Table 1
Box–Behnken design of experimental conditions and observed responses for TPC and antioxidant capacity (ABTS radical scavenging activity) of R.A. Poir leaf extracted using ultrasonic-assisted extraction.
Run
Factors
Actual (mg GAE/g)
Predicted (mg GAE/g)
Prediction error (%)
Actual (mg TE/g)
Predicted (mg TE/g)
Prediction error (%)
(W)a
(°C)a
(min)a
1
300 (0)
45 (0)
30 (0)
16.08
1.18
21.16
2.39
2
500 (+1)
45 (0)
55 (+1)
7.15
-0.14
8.97
0.22
3
300 (0)
45 (0)
30 (0)
16.57
0.06
21.39
0.23
4
300 (0)
45 (0)
30 (0)
15.46
0.06
20.59
2.87
5
100 (-1)
45 (0)
55 (+1)
12.54
0.32
17.48
0.17
6
300 (0)
30 (-1)
5 (-1)
8.53
0.35
13.19
0.30
7
300 (0)
60 (+1)
55 (+1)
6.54
-0.92
6.98
2.58
8
500 (+1)
45 (0)
5 (-1)
12.45
1.77
17.69
0.11
9
500 (+1)
60 (+1)
30 (0)
8.35
0.24
10.18
0.69
10
300 (0)
45 (0)
30 (0)
16.55
-0.06
22.33
-0.04
11
100 (-1)
30 (-1)
30 (0)
8.53
0.35
13.08
0.23
12
300 (0)
30 (-1)
55 (+1)
11.98
3.67
16.12
0.81
13
300 (0)
45 (0)
30 (0)
15.99
0.06
21.46
0.05
14
100 (-1)
45 (0)
5 (-1)
6.46
-0.62
6.51
-0.77
15
100 (-1)
60 (+1)
30 (0)
8.31
0.12
10.64
0.85
16
500 (+1)
30 (-1)
30 (0)
13.40
-0.37
18.37
0.16
17
300 (0)
60 (+1)
5 (-1)
8.64
-0.12
13.81
0.07
a,, and , respectively, denote the ultrasonic power (W), extraction temperature (°C), and extraction time (min). The values are .