Table 1. Experimental setup for five-level, five-factor central composite rotatable design in terms of coded, actual values of variables and experimental data.

Run
no.

  Water
content

Temperature

Enzyme
loadings

Acid/alcohol molar ratio

Molecular ieves

Yield

 X₁/%

X₂/ºC

X₃/mg g^-1

X₄

X₅/h

Y/%

1

1(0.7)

1(55)

1(49)

 1(2:1)

 1(15)

87.43

2

1(0.7)

1(55)

1(49)

-1(1:1)

-1(5)

48.18

3

1(0.7)

1(55)

-1(27)

 1(2:1)

-1(5)

49.84

4

1(0.7)

1(55)

-1(27)

-1(1;1)

 1(15)

21.51

5

1(0.7)

-1(35)

1(49)

 1(2:1)

-1(5)

93.69

6

1(0.7)

-1(35)

1(49)

-1(1:1)

 1(15)

80.18

7

1(0.7)

-1(35)

-1(27)

 1(2:1)

 1(15)

98.16

8

1(0.7)

-1(35)

-1(27)

-1(1:1)

-1(5)

76.18

9

-1(0.3)

1(55)

1(49)

 1(2:1)

-1(5)

82.95

10

-1(0.3)

1(55)

1(49)

-1(1:1)

 1(15)

57.51

11

-1(0.3)

1(55)

-1(27)

 1(2:1)

 1(15)

71.77

12

-1(0.3)

1(55)

-1(27)

-1(1:1)

-1(5)

23.29

13

-1(0.3)

-1(35)

1(49)

 1(2:1)

 1(15)

92.35

14

-1(0.3)

-1(35)

1(49)

-1(1:1)

-1(5)

77.07

15

-1(0.3)

-1(35)

-1(27)

 1(2:1)

-1(5)

88.32

16

-1(0.3)

-1(35)

-1(27)

-1(1:1)

 1(15)

70.84

17

2(0.9)

0(45)

0(38)

 0(3:2)

 0(10)

90.32

18

-2(0.1)

0(45)

0(38)

 0(3:2)

 0(10)

78.70

19

0(0.5)

2(65)

0(38)

 0(3:2)

 0(10)

36.56

20

0(0.5)

-2(25)

0(38)

 0(3:2)

 0(10)

81.97

21

0(0.5)

0(45)

2(60)

 0(3:2)

 0(10)

92.75

22

0(0.5)

0(45)

-2(16)

 0(3:2)

 0(10)

17.30

23

0(0.5)

0(45)

0(38)

 2(5:2)

 0(10)

100.00

24

0(0.5)

0(45)

0(38)

-2(1:2)

 0(10)

32.60

25

0(0.5)

0(45)

0(38)

 0(3:2)

 2(20)

90.33

26

0(0.5)

0(45)

0(38)

 0(3:2)

-2(0)

76.47

27^a

0(0.5)

0(45)

0(38)

 0(3:2)

 0(10)

73.21

28^a

0(0.5)

0(45)

0(38)

 0(3:2)

 0(10)

89.16

29^a

0(0.5)

0(45)

0(38)

 0(3:2)

 0(10)

84.51

30^a

0(0.5)

0(45)

0(38)

 0(3:2)

 0(10)

92.65

31^a

0(0.5)

0(45)

0(38)

 0(3:2)

 0(10)

79.16

32^a

0(0.5)

0(45)

0(38)

 0(3:2)

 0(10)

93.15