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close this bookSmall Scale Processing of Oilfruits and Oilseeds (GTZ, 1989, 100 p.)
close this folder3. Case Studies
View the document3.1 Shea nut processing by women in Mali
View the document3.2 Hand-operated sunflowerseed processing in Zambia
View the document3.3 Oil palm fruit processing as a women's activity in Togo

3.1 Shea nut processing by women in Mali


Since 1982, a GTZ/GATE/DMA project has been engaged in Mali to develop and disseminate a system for processing shea nuts that improves on the traditional system. For this project an oven, a hydraulic hand press and a cake-expel stand have been developed by KIT. After introductory tests, the local production of the equipment has been set up and the equipment is being disseminated.

Organization and management at the village level

In villages, where shea nut trees grow, practically all the women collect and process shea nuts. The collected nuts become the personal property of the collector and are stored in her own pits. The processing is traditionally carried out at the level of the extended family by a group of women, who assist the collector. Occasionally small quantities are processed by individuals.

Adaptation of the shea nut press means that the processing has to be carried out at the village level. As the village women are generally organized and headed by a president, who is assisted by a group of elder women, this is quite feasible. However,first of all, the men, headed by the village chief, have to advise. The installation of a press is a village affair and has to be approved and backed by the men. The contribution by the village (50 % of the total investment costs for equipment and building) is raised by the men and the women.

The president and some representatives of the women supervise and organize the utilization of the press. They are also the owners of the press. A treasurer has to collect a small fee from the owner of the nuts in proportion to the quantity processed; money which is to be kept separate. It serves as a reserve fund to cover expenses for maintenance, repair and amortization. To have the fund administered in a formal way, a literate person should be available. Otherwise, a more informal administrative system should be implemented.

The press is installed under supervision of the GTZ/GATE project. The group appoints a few women (some older, some younger) to be trained in the operation and maintenance of the press. These women assist the processors and will train them in turn. The way in which the press is utilized is essentially a service system, by which the press is made available to the women of the village for a fee. The owner of the nuts is responsible for the processing and must provide the operating crew.

Process and equipment

The nuts to be processed are removed from the pit, pre-dried in the sun and decorticated. The kernels are subsequently pounded into a powder (with particles smaller than 5 mm). If the powder is dry, some water (about 10 %) should be added and left to be absorbed for an hour at least. The mass is divided into 5 kg batches and heated in a pot over a fire (to about 120°C) and kept hot for about I hour in the oven. The hot mass is poured into a preheated cage and pressed. When pouring, the mass should be divided in small portions of about I kg by means of a pressplate. After pressing, the cage is removed from the press and put on the expel stand to expel the cake, after which the oil extraction process is repeated, using the oil cake as raw- material. For this second pressing, the cake should be pounded and sieved (to be sure that all particles are smaller than 2 mm) and water (about 10 %) should be added. Finally, the extracted oil, containing some brown particles, is boiled with a little water and some juice of okra and lemon, to obtain a clear, white oil. The oil is left to cool down to form a solid fat, called shea butter. The cake is used as fuel.

The equipment required consists of:

- an oven, made up of a fire-place with a pot (no. 15, contents 401) and a heated box to hold a few buckets, covered with lids,
- a hydraulic hand press (based on a 30-ton lorry jack and equipped with two press cages with pressplates),
- a cake expel stand (to remove the oil cake from the cages) and
- some minor equipment like mortar and pestles.

The cost of the press with expel stand is F CFA 400 000, for the oven FCFA 40 000 and for the minor equipment around F CFA 10 000 (1987 prices). F CFA 50 are equivalent to French F 1.0, which is approximately US $ 0.15.

Results and experience

Total working time required for processing 10 kg shea kernels is about 10 man hours, of which about 3 hours are required for the pounding. A group of five women, which is a common case, would process some 50 kg of kernels per working day on average. Experienced groups can process up to 80 kg per day. Oil recovery is, depending on the quality of the nuts, between 35 % and 42 % on dry kernels, sometimes even higher.

Women are pleased to use the press, because:

1. heating of the nuts in a traditional oven for about three days at least can be omitted, which saves a lot of firewood and time;

2. the mass is easier to pound, while the crushing between stones can be omitted, which makes the work much faster and lighter and saves therefore time and energy;

3. very little water is required, which saves a lot of work;

4. the oil recovery, which of course depends on the quality of the nuts, is higher than traditionally (an estimate is about 13.5% on dry kernels; i.e. 38.5% average yield against 25 % in the traditional process);

5. the cake, which traditionally is discarded, can be used as fuel.

Another positive aspect is that this technology can be mastered by women and that the men are not really interested to take it over. The most probable reason for this is that the crucial steps, such as “size reduction" and “cooking", are still carried out in the traditional way, by pounding and a pot-over-a-fire respectively.

Shea nut processing is mainly carried out in the dry season, when the harvest is over. However, if money is needed and the rawmaterial is available, the women process oil in August as well. In a village in South Mali, 27 women are recorded as using the press and 1350 kg nuts were pressed in one year (an average of 50 kg per woman per year). In the same village, women collected other oil seeds as well as Niam Seeds (Lophira alata) for food-oil, Physic Nut (Jatropha Curcas) and seeds of the wild olive (Ximenia americana) for soap-oil. This can be seen as a first attempt towards a diversified production and will have an additional positive effect on the amortization of the equipment.

Although the women were trained with care, many women had difficulties with technical aspects; particularly with the hydraulic jack equipment. In some cases, the release valve was completely unscrewed and the hydraulic oil was lost. Besides, the women had to develop a sympathetic understanding for the equipment in order to prevent damage, for instance by pumping long strokes at a steady rate to conserve the pump and to stop at a certain maximum pressure to protect the press and save energy.

Also, an understanding of the process required time. Refresher courses are needed in order to keep the operation up to the required standard. Regular maintenance appeared to be required as well. Young villagers and some women were trained to carry out small maintenance and repair jobs such as topping-up with hydraulic oil or renewing a pump seal.

Technically, the press appeared to be not without its problems. The jack pump showed not only rapid wear at its seal, but also of its mechanical parts. On the other hand it appeared that the jack was not sufficiently well supported by the frame, thus causing the base of the jack to break. An improved pump for the jack has recently been designed. Also the frame will be reinforced. It is expected that these improvements will have positive effects.

Nevertheless, due to the advantages of the new processing system and the start-up of a service and maintenance programme, the demand for the shea nut presses is steadily increasing. By early 1987, the GTZ/GATE/KIT shea nut processing equipment had been installed in 35 villages in Mali. In addition, enquiries from neighbouring countries are increasing in number. Recently, the new technology has been introduced to Burkina Faso after technicians and extension workers had been trained in Mali.


It cannot be expected that the cost of investment of F CFA 440000 for the technical items (oven parts, hydraulic press and expel stand) can be paid in full by any village. Therefore, the equipment is normally partly subsidized by the project or other international organizations. The village usually is expected to build the accommodation (for approximately F CFA 100 000 ) for the press and to raise a certain contribution for the equipment. A small fee is asked from the women (e.g. F CFA 25 per 5 kg bucket) for a reserve fund to finance maintenance, repair and amortization.

Alternative possibilities

For improving and facilitating the processing of shea nuts, an alternative solution is the use of a motorized grain mill. Because the processing of shea nuts makes the discs of the mill very sticky (requiring an extra cleaning procedure), many village millers are reluctant to make their grain mill available for the custom milling of shea nuts or alternatively demand much higher fees. If a motorized grain mill is available to the village, it is recommended to install a separate mill that can be driven by the same engine.

In Chapter 4, a financial appraisal is given based on the average price for nuts of F CFA 30 and for shea nut butter of F CFA 300 per kg, as prevailing in early 1987 in the rural areas of Mali. At that time, the local cost for milling of grain by a service mill was about F CFA 25 per kg.

Local production of equipment

To be able to start the distribution of the presses, local production had to be set up.

At first an existing construction company was given the opportunity to take up the production of the presses, guided by an expert from KIT. As it appeared that this company only wanted to continue if they could charge a 100 % profit, it was decided to establish a special production unit. A small partnership of craftsmen was advised by the GTZ/GATE project in establishing its own workshop with the press as the most important product. At present, this workshop manufactures the presses, supplies the spare parts and repairs the equipment, including the hydraulic jack. However, the supply of imported items, such as jacks and their spare parts, still gives problems. A reliable import line has yet to be organized.

3.2 Hand-operated sunflowerseed processing in Zambia


Since 1985, a project has been carried out in Zambia to establish a few fully handoperated sunflowerseed processing units, mainly financed by the government of the Netherlands. The objective of the project is to test the feasibility of hand-operated sunflowerseed processing in Zambia. As quite a few projects are interested in assisting the establishment of such units, a preparatory familiarization programme has already been started by the Technology Development and Advisory Unit (TDAU) of the University of Zambia (UNZA), Lusaka Campus. The equipment will be manufactured locally.

The test-units were established at the Kasisi Mission near Lusaka, at the Kaoma-TBZ Scheme and in the Gweembe Valley.

Organization and management at the unit level

The unit established at the Kasisi Mission is an example of a quite formal enterprise. The unit is an external activity of the Training Centre to whom it is responsible. The Training Centre as a whole is the responsibility of the fathers of the Kasisi Mission. The unit is operated by a group of six school-leavers, headed by a group leader. They work the normal working hours under the supervision of the Centre and are paid as agricultural labourers. The Centre constructed the building and provided the working capital. The equipment has been imported and was financed by outside assistance. Financial management is taken care of by the Mission and the seed is bought in the period just after harvest. All the seed required until the new season is bought before the prices for the new season are announced. The seed is stored at the Centre.

At the Kaoma-TBZ Scheme and in the Gweembe Valley, the units are operated by women's groups. At Kaoma-TBZ, the Kweseka women's group is responsible for the operation of the unit. Guidance is provided by the extension staff of the Ministry of Agriculture who made some working capital available for the procurement of seed.

In the Gweembe Valley, women's groups are responsible as well and are guided by staff of a project by the Gossner Mission, who provides the seed.

The Kasisi unit is well established. Its operation is described below as a typical example of how a well managed unit can operate.

Initially, a processing capacity of 3 bags or 150 kg per day was reached, but oil recovery was very low. This low oil recovery was caused, for example, by:

- improper dehulling and large losses of kernel material during this step,
- improper moistening, by not letting the water be absorbed for one hour,
- improper pressing, by not waiting long enough for all the oil to become released.

In May 1986, refresher training sessions given by the Kasisi mission father responsible for the centre, revealed that proper processing, carried out with discipline and using good seed, gave much better results as follows:

- early planted local seed (composite 75), with an oil content of 35.5 % gave 9.8 kg (or 10.31) oil per bag (19.6 % recovery on seed),
- late planted hybrid seed, with 37.0% oil gave 11.4 kg (or 12.0 1) oil per bag (24 % recovery on seed).

In September 1986, an evaluation showed that these figures were being realized on a continuous basis. A point that still needed special attention, however, was the adjustment of the clearance between the rollers of the roller mill.

The set-up at Kasisi works very well, mainly because of good leadership and management. By refresher sessions, technical problems with the process could be overcome, while maintenance and repair was easily cared for by the mission workshop.

The women's groups at Kaoma TBZ and in the Gweembe valley are lacking leadership and management. Also, refresher sessions are necessary to maintain standards of processing. The organizational system, by which the problems of these groups could be overcome, has still to be worked out.

Process and equipment

The process applied is the “dry process", including:

- dehulling of the seed (decorticating and winnowing)
- size reduction (crushing in a roller mill)
- cooking (moistening and heating)
- pressing (in a hydraulic hand press or in a spindle press).

At Kasisi and Kaoma-TBZ, the units are equipped with a CECOCO decorticator and winnower, and a KIT designed roller mill, heating unit and hydraulic hand press. In the Gweembe Valley, KIT designed dehulling equipment replaces the CECOCO equipment, and the UNATA spindle press replaces the hydraulic press.

To prepare for local production, these types of decorticator and winnower are currently being tested at Kasisi. Their performance and durability appear satisfactory. Unfortunately, the hydraulic press gives problems. The hydraulic system seems to be quite vulnerable and difficult to repair. Since the same pressing results can be obtained with a simple spindle press, which is also easier to manufacture and repair locally, it has been proposed to change to the UNATA spindle press.

At Kasisi, the operators start on a normal working day at 7 a.m., divided into three groups of two. Each group is charged with the processing of one bag (or 50 kg) sunflowerseed. The group that has finished the day before with crushing starts with mixing-in the water. After one hour they start heating, followed by pressing. (Between heating and pressing, the mass is kept hot in closed buckets in a kind of a hay-box.) After pressing, this group takes up decorticating followed by crushing to prepare the material for the next day. Another group starts with crushing followed by mixing in water, then heating and pressing. After pressing, they start decorticating to prepare for the next day. The third group starts with decorticating, followed by crushing, mixing in the water, heating and pressing. A complete cycle for 50 kg requires about 6 effective working hours. Some more time is required for preparatory work, rest to recover from heavy manual work and maintenance. The group takes a break at noon. At 2 p.m. the work is resumed until 5 p.m.

At Kaoma-TBZ, the women, when they were still motivated, worked~four days a week with ten persons, processing in three groups about 25 kg seed per group per day. Later on, the women's groups became smaller, and late 1986 they processed only 50 kg seed per day, two days a week.

Results and experience

The process was introduced at Kasisi in November 1985. The group was trained for one week. Due to problems of getting a license the production could not start before January 1986. Between January and mid-April the group worked quite independently and with little supervision. In total 11.4 tons of seed were processed and 16651 sunfloweroil sold. That equals a net production of 7.3 1 of oil per 50 kg bag of seed.


From January to April 1986, the financial results of the Kasisi unit were disappointing, as the income from oil could only cover rawmaterials and wages and no other costs. This was due to:

- low oil recovery (only 7.31 per bag of 50 kg)
- low production capacity at the beginning (below I SO kg per day)
- increased wages (an increase of about 50 %)
- low oil price (K 5.00 per 1, because subsidized oil flooded the market).

For the season 1986/87, the Mission had purchased the required 30 tons of sunflowerseed of good quality at the official price (K 42 per 50 kg bag) just in time, before the new producer prices (of 70 K per 50 kg bag) had been announced. A reasonable daily budget could therefore be made (see below).

The main problem for Kasisi will remain the difficult economic situation in the country, with steeply rising prices for sunflower seed to compensate for rising production costs, and heavily subsidized relatively constant prices of vegetable oil.

Because of the high sunflowerseed prices and the low oil prices, together with their low productivity, oil production in the 1986/87 season seems not to be remunerative enough for the women of the Kweseka group at Kaoma-TBZ. As long as this situation continues, not much production can be expected at Kaoma-TBZ. In the Gweembe Valley, sunflower seed is a little cheaper and oil a little more expensive, which makes oil production more remunerative. It is not yet known if this margin is interesting enough for the women concerned to take up oilseed processing on a continuous basis.

Expenses per day:

3 bags sunflowerseed @ K 42/bag


wages for 6 agricultural labourers


other costs


amortization equipment @ K 10/bag


amortization building @K 10/day




Income per day:

30 l oil at K 7 per I (just below price of subsidized oil, September 1986)


cake (used as animal feed by the mission)


Net Cash Income per day


Alternative possibilities

Alternatives for fully hand-operated sunflowerseed processing in Zambia are motorized expellers, as presented in Chapter 2. In Chapter 4, the feasibility of a locally manufactured hand-operated system is compared with the feasibility of alternative motorized expeller systems.

The price of a locally manufactured handoperated system (basis September 1986) is estimated at K 20 000. At that time, 1 K was equivalent to 0.17 US $.

3.3 Oil palm fruit processing as a women's activity in Togo


Early in 1986, the Togolese organization CONGAT requested KIT to introduce its improved system for oil palm fruit processing in Togo. The project was financed by the Dutch NGO: ICCO. In the framework of this programme, a unit for processing Tenera oil palm fruit was established at Agou Yiboe. The objective of the programme was to demonstrate the feasibility of this fully hand-operated system to improve the living conditions of women in the south of Togo.

Organization and management

The CFAE (Centre de Formation Agricole et Economique) at Agou-Yiboe, Togo, guides a group consisting of about 18 young women. In addition to the staff of the CFAE, the group is guided by a Canadian lady volunteer. A unit for processing tenera oil palm fruit has been established at the CFAE to provide the women with productive employment. Bunches of tenera oil palm fruit are made available as the rawmaterial to be processed by the CFAE from their own plantation. The price quoted to the group is the same as the CFAE gets from a nearby palm oil mill.

The group is headed by a- chairwoman, who is assisted by a core group of women. Originally, the group met for training sessions on the subject of hygiene, child care and needlework. Later on they started with agricultural work on their own account, raising crops such as maize. As the income earned by the women from agriculture was disappointing, the processing unit has been set up.

CONGAT has made the equipment available and the CFAE the working capital; equipment and working capital have to be reimbursed by the group. The staff of the CFAE assists in the management of the funds.

Process and equipment

The unit has been set up to process 500 kg of tenera oil palm fruit bunches per day, twice a week during 6 months of the year. The unit consists of an open shed and is equipped with the following equipment:

- a large cooking kettle for the steaming of bunches
- a threshing grid
- a concrete pounding mortar - 4 reheating kettles
- a hand-operated spindle press UNATA 420 1
- a clarification kettle
- cooking pots for oil drying.

The processing of oil palm fruit is carried out in the following way: about 500 kg of bunches are bought from the CFAE on the day before the actual processing is to be carried out. They are loaded into the steaming kettle and steamed for about four hours in the afternoon, under the supervision of two women.

The next day starts at 7 a.m., with threshing and pounding. The fruit is still warm, but not too hot to touch. As soon as a reheating drum has been filled, the fruit is reheated. This step can be the most crucial, since, if not carried out correctly, the oil recovery will be disappointingly low. Since the mass of pounded tenera fruit is quite solid and difficult to penetrate by steam, at least three hours are required for proper reheating. After finishing threshing and pounding, carried out by 8 women in about three hours, there is a pause for about one and a half to two hours as one has to wait for the reheating to be completed. Around noon, or a little later, pressing starts after which fibres and nuts are separated and the fibre is collected in an empty reheating drum and reheated again. The press fluid is collected in the clarification drum. The leak-oil, obtained during reheating, is put in an oil drying pot. When the pressing is finished, the oil collected in the clarification drum is skimmed off. The mass to be clarified is boiled, in the traditional manner, to obtain as much oil as possible. Finally, all oil is dried by heating and poured into clean drums for storage.

Results and experience

It appeared that about 10 women were required to process 500 kg of bunches into about 90 kg (or 961) palm oil in an 8 hour working day. The oil is sold on the open market. In fact more women assisted in the processing of this quantity. However, some did really work hard, while others were only looking for light jobs. To organize the processing and establish a good co-operation within the group, leadership is required.

Technically, no special problems arose. However, the understanding of the process gave some difficulties. A refresher session appeared to be necessary.

The operation itself is an example of a unit acting as an enterprise. In principle, such a set-up requires quite good management abilities, such as procurement of rawmaterial, sale of products as well as the operation of the unit. To simplify financial management, a service mill might be much more interesting. As only the money for the maintenance and amortization of the equipment and the labour has to be catered for, such an arrangement might be more easily realized.

What remains crucial in the case of a service mill is the leadership to maintain a good working spirit and discipline. The group could contract the processing of a certain quantity of bunches of palmfruit, against a payment in cash or in kind.


The bunches were made available to the group at F CFA 20 per kg. The oil could be sold at F CFA 200 per 1. Since there are seasonal price fluctuations, it would seem to be more beneficial to store the oil for later sale. However, this would require much more working capital. With a reasonable profit to be made by selling the oil directly, such a venture is not advisable. It complicates financial management unnecessarily. Total required investment in equipment is about F CFA 800 000.

Alternative possibilities

As an alternative to the KIT process, using a hand press, at least partly motorized alternatives are a possibility. There is the TCC pounding machine to replace the handpounding and the CALTECH or COLIN type press (SPEICHIM M-10) to replace both pounding by hand and pressing. As described under 2.2.1, 8 women can process about 600 kg of palmfruit per day using the TCC system. This would mean that about 900 kg bunches would have to be cooked and threshed. For the threshing alone, 4 women extra would be required. The motorized version of the CALTECH can process 200 kg steamed fruit per hour. For this only four persons would be required. However threshing would require additional manpower.

For an economic discussion, the threshing problem is better omitted. Chapter 4 will therefore compare the economic performance of the KIT system (8 women and about 400 kg palmfruit per day, giving 112 kg or 1201 palmoil) with alternatives such as the TCC system (8 women and about 600 kg palmfruit per day, giving 148 kg or 159 I palmoil) and the CALTECH (4 persons and about 800 kg palmfruit per day, giving 211 kg or 227 1 palmoil).