Development of a Novel Whey Date Beverage Fermented with Kefir Grains Using Response Surface Methodology
Table 3
Matrix of the central composite design (CCD) and observed responses for the response variables (DPPH scavenging activity, TPC, and overall acceptability).
Exp. no.
X1 (whey permeates % w/v)
X2 (date syrup % w/v)
X3 (kefir grains % w/v)
Response variables
DPPH scavenging activity (Y4)
Total phenolic content (mg GAE/mL) (Y5)
Overall acceptability (Y6)
1
1.0
18
2.6
90.70 ± 0.89
27.00 ± 0.89
4.10 ± 0.14
2
4.0
18
2.6
74.80 ± 0.26
41.00 ± 0.69
4.20 ± 0.01
3
1.0
42
2.6
91.37 ± 0.96
67.00 ± 0.02
6.80 ± 0.12
4
4.0
42
2.6
89.05 ± 0.76
74.00 ± 0.27
6.00 ± 0.00
5
1.0
18
4.4
91.12 ± 0.83
36.00 ± 0.55
4.10 ± 0.02
6
4.0
18
4.4
90.02 ± 0.38
25.00 ± 0.00
4.00 ± 0.00
7
1.0
42
4.4
83.02 ± 0.88
45.00 ± 0.14
6.50 ± 0.67
8
4.0
42
4.4
90.19 ± 0.28
34.00 ± 1.11
6.20 ± 0.17
9
−0.0
30
3.5
90.44 ± 0.49
40.00 ± 0.70
5.00 ± 0.18
10
5.0
30
3.5
84.43 ± 0.82
44.00 ± 0.96
4.70 ± 0.35
11
2.5
10
3.5
89.99 ± 0.00
25.00 ± 0.01
3.30 ± 0.42
12
2.5
50
3.5
86.71 ± 0.41
55.00 ± 0.31
6.60 ± 0.01
13
2.5
30
2.0
87.68 ± 0.43
60.00 ± 0.11
6.80 ± 0.23
14
2.5
30
5.0
91.46 ± 0.67
28.00 ± 019
5.10 ± 0.05
15
2.5
30
3.5
90.68 ± 1.08
25.00 ± 0.93
3.80 ± 0.13
16
2.5
30
3.5
91.06 ± 0.10
24.00 ± 0.00
3.70 ± 0.28
17
2.5
30
3.5
90.56 ± 0.67
24.00 ± 0.56
3.50 ± 0.14
18
2.5
30
3.5
91.10 ± 0.16
25.00 ± 0.42
3.60 ± 0.12
19
2.5
30
3.5
91.02 ± 0.06
23.00 ± 0.00
3.70 ± 0.20
Overall acceptability scored on the nine-point Hedonic scale.
