2 Industrial Plant Oil Extraction
77
As shown in Fig. 2.7c, when the reaction condition of hydrolysis time (h), enzyme
concentration (%), and ratios of material to water (w/v) were maintained at 4 h, 2%,
and 1:4, respectively. The hydrolysis temperature (range from 40 to 60 °C) has a big
influence on the oil recovering rate which dramatically effects the activity of enzymes.
In this study, the temperature ranges from 45 to 55 °C had the best performance on
the oil recovering rate (p < 0.05). When the hydrolysis temperature was below 45
or exceeded 55 °C, it led to the lower oil yield which might be attributed to the
deactivating of the enzymes.
The reaction condition of hydrolysis time (h), hydrolysis temperature (°C), and
ratios of material to water (w/v) were maintained at 4 h, 50 °C, and 1:4, respectively.
The concentration of enzyme is a vital factor in aqueous enzymatic extraction. The oil
recovering rate increased with enzyme concentrations, whereas, there was no significant increase in the oil recovering rate when the enzyme concentration increased from
3 to 4% (p > 0.05) (Fig. 2.7d). In the perspective of industrial applications, enzyme
dosage reduction would decrease the cost under the stable oil yield achievement,
therefore, 3% would be more suitable for aqueous enzymatic extraction.
2.6.2.3 Physicochemical Properties Determination
Physicochemical properties of castor seed oil like acid, iodine saponification, and
hydroxyl values are the most important characteristics of oil. The acid, saponification,
iodine, and hydroxyl value and of castor seeds oil samples were determined according
to AOCS standard methods (1998). The acid was determined by Sodium hydroxide
titration and calculated in terms of milligrams of potassium hydroxide necessary
to neutralize the free acids in 1 g of oil sample. The iodine value is expressed in
grams of iodine which react with 100 g of the oil sample to saturates, saponification
value is represented the number of milligrams of potassium hydroxide required to
saponify 1 g of oil sample, and is defined as the number of milligrams of potassium
hydroxide required to neutralize the acetic acid taken up on acetylation of one gram
of a chemical substance that contains free hydroxyl groups. The refractive index
(R.I.) was determined using an RM40 automatic refractometer (Mettler Toledo Co.,
Ltd., Switzerland), and the results were standardized at 25 °C.
Fatty acid components of the oil were analyzed using Clarus 600 gas
chromatograph-mass spectrometer (GC-MS, Perkin Elmer Instrument Co., Ltd.,
Shanghai, China). Oil sample was methyl esterified in 0.5 mol/L blending solution
of potassium hydroxide (KOH) and methyl alcohol, and then stratified in petroleum
ether with deionized water, and centrifuged under 3000 r/min for 5 min, the saponified fruit oil injected into a free fatty acid polyester (FFAP) column (0.3 mm × 25 m).
Oven temperature was programmed as follows: held at 40 °C for 1 min, increased to
100 °C at 20 °C per min and held at 100 °C for 2 min, increased to 220 °C at 20 °C
per min and held at 220 °C for 2 min, increased to 240 °C at 20 °C per min and held
at 240 °C for 5 min. Carrier gas, helium (He), was provided at a flow rate of 1.1 per
min in the column. The injector temperature was 210 °C, and the injection volume
was 1 μL. GC and MS interface temperature and ion source temperature was 230
77
As shown in Fig. 2.7c, when the reaction condition of hydrolysis time (h), enzyme
concentration (%), and ratios of material to water (w/v) were maintained at 4 h, 2%,
and 1:4, respectively. The hydrolysis temperature (range from 40 to 60 °C) has a big
influence on the oil recovering rate which dramatically effects the activity of enzymes.
In this study, the temperature ranges from 45 to 55 °C had the best performance on
the oil recovering rate (p < 0.05). When the hydrolysis temperature was below 45
or exceeded 55 °C, it led to the lower oil yield which might be attributed to the
deactivating of the enzymes.
The reaction condition of hydrolysis time (h), hydrolysis temperature (°C), and
ratios of material to water (w/v) were maintained at 4 h, 50 °C, and 1:4, respectively.
The concentration of enzyme is a vital factor in aqueous enzymatic extraction. The oil
recovering rate increased with enzyme concentrations, whereas, there was no significant increase in the oil recovering rate when the enzyme concentration increased from
3 to 4% (p > 0.05) (Fig. 2.7d). In the perspective of industrial applications, enzyme
dosage reduction would decrease the cost under the stable oil yield achievement,
therefore, 3% would be more suitable for aqueous enzymatic extraction.
2.6.2.3 Physicochemical Properties Determination
Physicochemical properties of castor seed oil like acid, iodine saponification, and
hydroxyl values are the most important characteristics of oil. The acid, saponification,
iodine, and hydroxyl value and of castor seeds oil samples were determined according
to AOCS standard methods (1998). The acid was determined by Sodium hydroxide
titration and calculated in terms of milligrams of potassium hydroxide necessary
to neutralize the free acids in 1 g of oil sample. The iodine value is expressed in
grams of iodine which react with 100 g of the oil sample to saturates, saponification
value is represented the number of milligrams of potassium hydroxide required to
saponify 1 g of oil sample, and is defined as the number of milligrams of potassium
hydroxide required to neutralize the acetic acid taken up on acetylation of one gram
of a chemical substance that contains free hydroxyl groups. The refractive index
(R.I.) was determined using an RM40 automatic refractometer (Mettler Toledo Co.,
Ltd., Switzerland), and the results were standardized at 25 °C.
Fatty acid components of the oil were analyzed using Clarus 600 gas
chromatograph-mass spectrometer (GC-MS, Perkin Elmer Instrument Co., Ltd.,
Shanghai, China). Oil sample was methyl esterified in 0.5 mol/L blending solution
of potassium hydroxide (KOH) and methyl alcohol, and then stratified in petroleum
ether with deionized water, and centrifuged under 3000 r/min for 5 min, the saponified fruit oil injected into a free fatty acid polyester (FFAP) column (0.3 mm × 25 m).
Oven temperature was programmed as follows: held at 40 °C for 1 min, increased to
100 °C at 20 °C per min and held at 100 °C for 2 min, increased to 220 °C at 20 °C
per min and held at 220 °C for 2 min, increased to 240 °C at 20 °C per min and held
at 240 °C for 5 min. Carrier gas, helium (He), was provided at a flow rate of 1.1 per
min in the column. The injector temperature was 210 °C, and the injection volume
was 1 μL. GC and MS interface temperature and ion source temperature was 230