2 Industrial Plant Oil Extraction
73
2.6.2.1 Aqueous Enzymatic Extraction (AEE)
The oilseed material was weighed (w 0 , g) and mixed with distilled water at a ratio
of 1:3(w/v) using a flask. The mixture was subjected to boiling (100 °C) for 10 min
and allowed to cool down to room temperature (25 °C). The pH was then set to the
suggested point for each enzyme or enzymatic combination using 0.5 N aqueous
NaOH or 0.5 N aqueous HCl solutions. Then, an amount (2.0% by seed kernels
material weight) of each of the five enzymes or enzymatic combinations (cellulase,
hemicellase, pectinase, amylase, and nutrase) was added. The conditions of temperature, pH, and reaction time used for these enzymes and enzymatic combinations are
given as ranges in Tables 2.8 and 2.9. The mixture was incubated at the suggested
temperature for corresponding pH and time with regular shaking at 120 rpm (e.g., in
Table 2.9, nutrase + cellulase, temperature 55 + 45 °C, pH 7.0 + 4.5, time 2 + 2 h,
Table 2.8 Effect of different enzymes on the oil recovering rate of castor seeds
Enzyme
EC
number
Enzymatic activity
(U/mg)
Initial
pH
Temperature
(°C)
Oil
recovering
rate (%)
Cellulase
EC 3.2.1.1 ≥400
4.5
45
45.35 ± 2bc
Hemicellase
EC
3.1.1.73
0.3–3.0
4.5
45
53.01 ± 2b
Pectinase
EC
3.2.1.15
≥500
8.0
60
55.12 ± 3b
Amylase
EC 3.2.1.1 380
7.0
45
37.31 ± 2c
Nutrase
EC
3.4.24.39
50
7.0
55
63.23 ± 3a
No enzyme
–
–
7.0
45
9.16 ± 3d
Table 2.9 Effect of different enzymatic combinations on the oil recovering rate of castor seeds
Enzyme
Temperature (°C) Initial pH Hydrolysis time
(h)
Oil recovering
rate (%)
Nutrase +
cellulase
55 + 45
7.0 + 4.5 2 + 2
60.62 ± 1a
Nutrase +
hemicellase
55 + 45
7.0 + 4.5 2 + 2
55.23 ± 1b
Nutrase +
pectinase
55 + 60
7.0 + 8.0 2 + 2
56.67 ± 2b
Cellulase +
pectinase
45 + 60
4.5 + 8.0 2 + 2
50.55 ± 2bc
Cellulase +
hemicellase
45
4.5
4
48.02 ± 1bc
Pectinase +
hemicellase
60 + 45
8.0 + 4.5 2 + 2
56.22 ± 2b