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The
Intermediate Technology Development Group (ITDG) in Zimbabwe
looked at machines appropriate for the small-scale processing of oil
seed crops – mainly sunflower. The oil mills introduced have
brought many benefits to the surrounding areas. Farmers have a good
market for their seed, people benefit from cheaper, good quality
cooking oil and the mills bring employment.
Moringa
oil has been used in skin preparations and ointments since Egyptian
times. The bright yellow oil with a pleasant taste has been compared
in quality with olive oil. The kernel contains 35–40% by
weight of
oil. Recent studies in Ghana show that soap made with moringa oil was
extremely good. Trials on extracting oil from moringa were carried
out with the enthusiastic assistance of Keith Machell.
Extraction
techniques
Moringa
seed has a fairly soft kernel, so the oil can be extracted by hand
using a screw press (also known as a ‘spindle’ or
‘bridge’
press). The seed is first crushed, 10% by volume of water is added,
followed by gentle heating over a low fire for 10–15 minutes,
taking care not to burn the seed. One such test yielded 2.6 litres of
oil from 11kg of kernels. Once the best processing conditions are
worked out, an extraction efficiency of 65% could probably be
expected.
Further
trials were carried out using a motor-driven screw-type oil expeller
from India. During 2 hours of operation 52kg of seed yielded 12.5
litres of cold pressed oil. A further processing of the oil cake
yielded a further 10 litres of oil.
Traditional
methods of extracting oil from oil seed crops are often slow and not
very efficient. They involve extracting the kernels, pounding them
and boiling them for 5 minutes in water. After boiling, strain
through a cloth into a clean container. Leave overnight to allow the
oil to separate from the water. There may be some debris floating on
the surface of the oil. Tribesmen in Oman use this technique to
extract oil from Moringa
peregrina seed with some
success. If you don’t have access to a machine, try out this
method.
After
the oil is extracted, the rather bitter tasting presscake still has
all the properties of fresh seed in treating and cleaning water. With
a 60% protein content, it may be used as a soil fertiliser and
further study is looking at how it could be used as part of animal
and poultry feed.
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