Extraction, Optimization and Characterization of Oil from Ethiopian Jatropha Seed Kernels Using Solvent Extraction Method
No Thumbnail Available
Date
2017-11
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
In this study, the seed of Jatropha curcas was collected from Bati of Amhara Region and it was
utilized for determination of proximate and mineral composition analysis of the seed, oil extraction,
characterization, and optimization. The Jatropha curcas oil was extracted using normal hexane (62—
78°C) by Soxhlet apparatus. The result showed that the seed kernels consisted of: 55.30% ( w/w) oil,
moisture (6.3621% w/w), total ash (5.25 % w/w), crude protein (21.59 % w/w), crude fat (46.57 %
w/w), crude fiber (16.77 % w/w) and carbohydrate (3.4%w/w) as its proximate analysis; and Na
(31.99 mg/100g), K (1159 mg/100g), Ca (8.65 ppm), Zn (0.308 ppm) and P (0.03g/100g) as the
main mineral profile of the seed. After optimization using Design-Expert has been carried out,
optimal conditions of temperature (70
C), solvent to solid ratio (10:1), and particle size (0.66mm)
have been obtained and an oil yield of 55.28% by wt. was found. After the optimum values have
been obtained, an experiment has been conducted and an oil yield of 54.81% by wt. was found
which is closely in agreement with the result obtained from the model and the experimental
observation and hence validated the findings of the optimization. Physicochemical characterization
of the optimized oil yield revealed that it has the following most important properties: moisture and
volatile matter (15.4883% w/w), kinematic viscosity (0.014mm
o
C, specific gravity (0.8567)
at 20
2
o
) at 40
o
C, acid value
(13.0152 mg KOH g-1 oil), free fatty acid value (6.5076 % by wt.), saponification value (140.25 mg
KOH g-1 oil), iodine value (104 g I2/100 g), and ash content (0.0811 % by wt.). From the FT-IR
result, different functional components like alcohols, phenols, alkanes, easters, aldehydes were
identified. The GC-MS analysis result of J. curcas oil showed that the presence of the following
major fatty acids: oleic acid (44.61%), palmitic acid (22.55%), linolic acid (13.64%), stearic acid
(8.64%), myristic acid (2.63%), 11-Hexadecenoic acid (1.85%) and other acids (6.08%).
Description
Keywords
Jatropha seed oil, extraction, physicochemical characterization, optimization, response surface methodology, yield