Response Surface Optimisation for the Production of Antioxidant Hydrolysates from Stone Fish Protein Using Bromelain
Table 1
Experimental and predicted values of response variables for central composite design.
Run order
variables
variables
(DH, %)
(DPPH• scavenging activity, %)
(Fe2+-chelating activity, %)
Uncoded levels
Experimental
Predicted
Experimental
Predicted
Experimental
Predicted
(1)
4.0
70
2.00
30
34.49
36.34
13.76
13.26
13.86
16.04
(2)
5.5
55
1.25
195
56.66
54.64
47.26
45.99
16.96
18.57
(3)
5.5
55
0.50
195
42.10
43.68
47.62
49.57
7.48
7.44
(4)
4.0
70
0.50
360
29.96
31.17
22.98
24.67
10.05
8.91
(5)
5.5
55
1.25
360
57.82
55.52
54.98
56.22
19.37
18.40
(6)
7.0
55
1.25
195
43.00
44.19
30.56
32.69
29.77
30.17
(7)
7.0
40
0.50
360
32.25
32.41
33.18
34.97
14.80
13.13
(8)
7.0
40
0.50
30
23.96
24.35
32.92
30.72
15.54
13.48
(9)
4.0
70
0.50
30
28.25
28.03
21.55
20.41
11.26
9.25
(10)
4.0
40
2.00
360
51.99
53.34
23.52
22.74
17.75
18.18
(11)
5.5
55
1.25
195
54.81
54.64
44.98
45.99
19.02
18.57
(12)
7.0
70
0.50
30
29.25
28.43
26.82
25.49
8.76
10.99
(13)
4.0
40
0.50
360
31.89
32.00
32.55
29.90
10.98
11.39
(14)
5.5
40
1.25
195
51.86
53.83
33.65
34.47
14.32
12.84
(15)
5.5
70
1.25
195
57.56
55.45
27.82
29.24
8.64
10.35
(16)
5.5
55
1.25
195
53.56
54.64
47.26
45.99
18.84
18.57
(17)
5.5
55
2.00
195
58.64
56.20
39.95
42.41
13.95
14.23
(18)
5.5
55
1.25
195
53.95
54.64
46.65
45.99
18.14
18.57
(19)
5.5
55
1.25
195
54.05
54.64
46.86
45.99
16.40
18.57
(20)
7.0
40
2.00
360
50.62
49.13
29.05
27.82
18.43
19.92
(21)
5.5
55
1.25
30
41.98
43.41
50.96
51.96
23.20
18.75
(22)
4.0
40
0.50
30
25.03
23.95
24.50
25.64
9.91
11.74
(23)
7.0
70
0.50
360
32.90
31.57
27.91
29.75
8.21
10.65
(24)
4.0
70
2.00
360
51.25
52.50
17.20
17.52
18.01
15.69
(25)
7.0
40
2.00
30
26.69
28.06
22.26
23.56
20.00
20.26
(26)
7.0
70
2.00
30
32.65
32.14
18.42
18.34
19.37
17.78
(27)
4.0
40
2.00
30
34.68
32.26
16.68
18.48
17.75
18.52
(28)
4.0
55
1.25
195
48.14
46.09
27.49
27.61
28.60
28.43
(29)
5.5
55
1.25
195
53.82
54.64
49.18
45.99
16.16
18.57
(30)
5.5
55
1.25
195
53.79
54.64
48.65
45.99
19.56
18.57
(31)
7.0
70
2.00
360
47.25
48.30
24.81
22.59
18.96
17.44
variables for hydrolysis of stone fish protein: ; pH, ; temperature (°C), ; enzyme/substrate ratio and ; time (min). variables: ; degree of hydrolysis (DH, %), ; 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•) scavenging activity (%) and ; Fe2+-chelating activity (%).
