It is generally agreed that the Oil Palm (Elaeis guineensis) originated in the tropical rain forest region of West Africa. The main belt runs through the southern latitudes of Cameroon, Côte d’Ivoire, Ghana, Liberia, Nigeria, Sierra Leone, Togo and into the equatorial region of Angola and the Congo. Processing oil palm fruits for edible oil has been practiced in Africa for thousands of years, and the oil produced, highly coloured and flavoured, is an essential ingredient in much of the traditional West African cuisine. The traditional process is simple, but tedious and inefficient.
During the 14th to 17th centuries some palm fruits were taken to the Americas and from there to the Far East. The plant appears to have thrived better in the Far East, thus providing the largest commercial production of an economic crop far removed from its centre of origin.
Palm oil is rich in carotenoids, (pigments found in plants and animals) from which it derives its deep red colour, and the major component of its glycerides is the saturated fatty acid palmitic; hence it is a viscous semi-solid, even at tropical ambients, and a solid fat in temperate climates.
Because of its economic importance as an high-yielding source of edible and technical oils, the oil palm is now grown as a plantation crop in most countries with high rainfall (minimum 1 600 mm/yr) in tropical climates within 10° of the equator. The palm bears its fruit in bunches (Fig.1) varying in weight from 10 to 40 kg. The individual fruit, (Fig. 2) ranging from 6 to 20 gm, are made up of an outer skin (the exocarp), a pulp (mesocarp) containing the palm oil in a fibrous matrix; a central nut consisting of a shell (endocarp); and the kernel, which itself contains an oil, quite different to palm oil, resembling coconut oil.
Origin of Plam Oil
Structure of the palm fruit
Fresh fruit bunch (ffb)
Fresh fruit (on the left is a cut fruit)
The wild oil palm groves of Central and West Africa consists mainly of a thick-shelled variety with a thin mesocarp, called Dura. Breeding work, particularly crosses between Dura and a shell-less variety (Pisifera), have led to the development of a hybrid with a much thicker mesocarp and a thinner shell, termed Tenera. All breeding and planting programs now use this latter type, the fruits of which have a much higher content of palm oil than the native Dura.
The extensive development of oil palm industries in many countries in the tropics has been motivated by its extremely high potential productivity. The oil palm gives the highest yield of oil per unit area compared to any other crop and produces two distinct oils - palm oil and palm kernel oil - both of which are important in world trade.
Modern high-yielding varieties developed by breeding programs, under ideal climatic conditions and good management, are capable of producing in excess of 20 tonnes of bunches/ha/yr, with palm oil in bunch content of 25 percent. This is equivalent to a yield of 5 tonnes oil/ha/yr (excluding the palm kernel oil), which far outstrips any other source of edible oil.
Ideal composition of palm fruit bunch
Bunch weight...........23-27 kg
Fruit/bunch..............60-65 %
Oil/bunch.................21-23 %
Kernel/bunch...........5-7 %
Mesocarp/bunch......44-46 %
Mesocarp/fruit.........71-76 %
Kernel/fruit..............21-22
Shell/fruit.................10-11
However, such high yields are rarely achieved in practice because climatic conditions are usually less than ideal. Rainfall is erratic in Central and West Africa and hence the tree suffer water-related stresses. The management of costly inputs of labour, imported fertilizers, pesticides and harvesting machinery, is also a difficulty that hampers the yield of plantations.
Early trading in palm products
International trade in palm oil began at the turn of the nineteenth century, while that of palm kernels developed only after 1832. Palm oil became the principal cargo for slave ships after abolition of the slave trade. The establishment of trade in palm oil from West Africa was mainly the result of the Industrial Revolution in Europe. As people in Europe began to take sanitation and hygiene seriously, demand for soap increased, resulting in the demand for vegetable oil suitable for soap manufacture and other technical uses. Tinplating required technical oil for which palm oil was found suitable. In the early 1870s exports of palm oil from the Niger Delta were 25 000 to 30 000 tonnes per annum and by 1911 the British West African territories exported 87 000 tonnes.
The export of palm kernels also began in 1832 and by 1911 British West Africa alone exported 157 000 tonnes of which about 75 percent came from Nigeria. Nigeria was the largest exporter until 1934 when the country was surpassed by Malaysia. Africa led the world in production and export of palm oil throughout the first half of the 20th century, led by Nigeria and Zaire. By 1966, however, Malaysia and Indonesia had surpassed Africa’s total palm oil production. According to Oil Palm Review, published by the Tropical Development and Research Institute in the United Kingdom, over 3 million tonnes of palm oil was produced by Malaysia alone in 1983, compared with a total of about 1.3 million tonnes of African production.
This publication does not intend to discuss the factors leading to the spectacular performance of Indonesia and Malaysia. However in these countries solid research and development has been undertaken backed by a conscious desire to implement research findings. The plantation development culture acquired from long cultivation and processing of latex rubber was a good foundation on which to introduce the large-scale plantation cultivation of palm oil. Mastery of technology and rapid mechanisation, together with government support to the industry as a systematic and strategic industrial development policy, facilitated private sector investment in this sector. These factors as well as many others have all played a part in the development of the Far East’s rise to prominence in the oil palm industry.
Oil palm farm systems in Africa
The primary unit of production of the palm oil industry is the farm where the oil palm tree is cultivated to produce palm fruits. There are also wild groves of oil palm. The farm units are of different sizes and may be classified as small, medium, and large-scale estates.
The wild groves, as the name implies, grow untended in the forest. They are found in clusters and are mainly the result of natural seed dispersal. Dura, the main variety found in the groves, for decades has been the source of palm oil - well before modern methods of oil palm cultivation were introduced to Africa in the second quarter of the 20th century.
The other varieties are Pisifera and Tenera, which is a hybrid variety obtained by crossing Dura and Pisifera. The Dura has a large nut with a thick shell and thin mesocarp. The Pisifera is a small fruit with no shell. By crossing the Dura with Pisifera a fruit is obtained with a thick mesocarp containing much more oil and fat (chemically saturated oil) than either of its parents. The Tenera nut is small and is easily shelled to release the palm kernel. The Tenera palm kernel is smaller than the Dura kernel although the Tenera bunch is much larger than Dura. In all, the Tenera is a much better variety for industrial and economic purposes.
Unfortunately, traditional farmers in Africa have not embraced the Tenera because consumers complained that the palm oil produced from the variety was too fatty. This means that when the oil cools to ambient temperature it ‘goes to sleep’ or solidifies instead of remaining fluid and red. The oil did not have the right taste as oil or as a soup base. Extension officers failed to position the Tenera as high-yielding industrial purpose oil, as opposed to oil for home cooking. The negative perception of Tenera led to its slow adoption and the failure of Africa to maintain its lead in palm oil production.
Small-scale farms
Plantation farming is a new phenomenon to West African culture. In most parts of Africa the farm culture is basically subsistence. The family cultivates a small plot for their food needs and interplant tree crops. After three years or more the tree crop takes over the plot and the farmer moves to another. The new plot may be acquired from the Chief in a location far removed from the old plot. Farm-holdings are therefore small and scattered. The land tenure system does not permit large-scale farming unless the government steps in to acquire the land for public use. Thus it is difficult to think of one family owning a large contiguous estate suitable for plantation farming.
A small-scale palm oil farm may cover 7.5 hectares. The farm’s production of fruits may be processed by the farmer, using the traditional method of palm oil extraction, or sold to other processors. During the lean season the farmer sells to the small-scale processors at prices higher than those offered to the larger mills. The small-scale farms are normally well maintained even though they may not adopt modern agronomic practices such as application of fertilizer, cover cropping, etc. to improve soil fertility and yields.
Medium-scale farms
The medium-scale farm ranges from 10 to 500 hectares. This type of farm normally uses modern agronomic practices such as plant spacing, cover cropping, fertilization, ring weeding, pruning, etc. Some farmers in this category own processing facilities and therefore use their own output as well as buying from neighbours. Those who do not own mills face marketing problems during the peak season when fruit is abundant and processors do not have to forage for raw materials.
Because the fruits are perishable and lose weight once harvested, farmers need prompt payment and evacuation of their fruits. If the roads are impassable they may suffer great loss of produce and income making it difficult for these farmers to finance their operations. As a result a number of farmers in this category are unable to adequately maintain their farms, resulting in decreased output from year to year.
Large-scale farms
Large-scale farms cover an area in excess of 500 hectares. These are state owned enterprises which were established to meet the internal consumption needs of the country and provide a surplus for export. The estates are well run and maintained. They employ the best farming techniques and employ highly skilled professionals to work their operations. Unfortunately they are always considered intruders in the communities where they operate, simply because they employ people who are not natives of the immediate catchment area.
Most estates are being privatised or sold to private interests in an effort to wean the respective governments from directly engaging in competitive businesses. Most estates had nucleus farms with out-growers and private smallholders supplying raw palm fruit to the central processing factory. The processing facilities were generally in the large-scale category.
Because of privatization exercises some large-scale processing operations have closed, leaving plantation output to be sold to small-scale processors. It is not unusual today to find many small-scale processing operations exploiting the splitting up of a plantation estate. The Republic of Benin, Cameroon and Ghana abound with examples of this type of take-over by small-scale operators.
Principles of preservation and processing methods
The general principles of preservation include:
- Destruction of enzymes (a complex organic substance which in solution produces fermentation and chemical changes in other substances apparently without undergoing any change itself) in the raw material and contaminating micro-organisms by heat (sterilization) during processing;
- Elimination of as much water as possible from the oil to prevent microbial growth (bacterial activity, or disease-causing germs) during storage. The oil therefore has a long shelf life due to its low moisture content.
- Proper packaging and storage of the extracted oil to slow down chemical deterioration (rancidity).
The method used to extract vegetable oil depends on the type of raw material available. Raw materials may be grouped according to the part of the plant that contains the fat or oil (seed, bean, nut or fruit). The main difference in raw materials is the moisture content. Raw materials with low moisture content include seeds and beans and some nuts, which are dried on harvest. Palm fruit, olive fruits and some coconuts are processed wet.
Only seeds, nuts and fruits that contain considerable amounts of edible oil are used for small-scale oil extraction. Other types (for example maize) may contain edible oil, but the quantities are too small for economic processing on a small-scale. However, not all oil-rich seeds and fruits have edible oil; some contain toxins (poisons, usually of bacterial origin) or have unpleasant flavours; these are used only for varnishes, paints, etc. Others, (for example castor oil) need very careful processing to make them safe for use as medicines. These are not suitable for small-scale processing.
Palm fruit contains about 56 percent oil (25 percent on a fresh fruit bunch basis) which is edible with no known toxins. It is thus suitable for small-scale processing.
Source : http://www.fao.org
