Oil Palm  - Elaeis guineensis
 
TAXONOMY

The African oil palm, Elaeis guineensis Jacq., is placed in the Arecaceae family along with coconut and date palms.
    
Cultivars
    There are three naturally occurring forms of the oil palm fruit, termed dura, tenera, and pisifera. Most cultivars are the tenera form which produces fruit with higher oil content.
 
ORIGIN, HISTORY OF CULTIVATION

     The African oil palm is native to tropical Africa, from Sierra Leone in the west through the Democratic Republic of Congo in the east. It was domesticated in its native range, probably in Nigeria, and moved throughout tropical Africa by humans who practiced shifting agriculture at least 5000 years ago. European explorers discovered the palm in the late 1400's, and distributed it throughout the world during the slave trade period. In the early 1800s, the slave trade ended but British began trading with west Africans in ivory, lumber, and palm oil.  The oil palm was introduced to the Americas hundreds of years ago, where it became naturalized and associated with slave plantations, but did not become and industry of its own until the 1960s. The first plantations were established on Sumatra in 1911, and in 1917 in Malaysia. Oil palm plantations were established in tropical America and west Africa about this time, and in 2003, palm oil production equaled that of soybean, which had been the number one oil crop for many years.

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PRODUCTION

World (2004 FAO) - 153,578,600 MT or 338 billion pounds. This is about twice the level of production of any other fruit crop, making oil palm by far the world's number one fruit crop. Oil palm is produced in 42 countries worldwide on about 27 million acres. Average yields are 10,000 lbs/acre, and per acre yield of oil from African oil palm is more than 4-fold that of any other oil crop, which has contributed to the vast expansion of the industry over the last few decades.

Top 10 Countries
(% of world production)
1. Malaysia (44%) 6. Cote d'Ivoire (1%)
2. Indonesia (36%)
7. Ecuador (1%)
3. Nigeria (6%) 8. Cameroon (1%)
4. Thailand (3%) 9. Congo (1%)
5. Colombia (2%) 10. Ghana (1%)

United States - No production
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BOTANICAL DESCRIPTION

Plant
    Oil palm can reach 60-80 ft in height in nature, but is rarely more than 20 or 30 ft in cultivation. Leaf bases are persistent for years, and prominent leaf scars are arranged spirally on the trunk of mature palms where bases have fallen. Leaves are  up to 25 ft in length, with leaflets numbering 200-300 per leaf, about 3-4 ft long and 1.5 - 2.0" wide, with entire margins. Leaflets cover the distal 2/3 of the leaf, and the lower 1/3 is spined with spines increasing in length acropetally.

Flowers
    Oil palms are monoecious, producing male and female inflorescences in leaf axils. The inflorescence of both sexes is a compound spadix with 100-200 branches, initially enclosed in a spathe or bract that splits 2 weeks prior to anthesis.


Male (left) and female (right) inflorescences of oil palm. Both are a compound spadix. Note the beetle pollinators foraging on the male flowers at the tips of the spadix branches.

Pollination
    Oil palms are primarily insect pollinated by various insects: in Africa, weevils (Elaeidobius spp), in Latin America, Mystrops costaricensis and Elaeidobius spp.

Fruit
    As in many palms, fruits are drupes. The mesocarp and endocarp vary in thickness, with dura types having thick endocarps and less mesocarp, and tenera types the opposite.  The exocarp color is green changing to orange at maturity in virescens types, and orange with brown or black cheek colors in the nigrescens types. Fruit range in size from <1" to 2", and are obovoid in shape. The mesocarp, from which palm oil is derived, is fibrous and oily, and the seed is opaque white, encased in a brown endocarp; palm kernel oil is derived from seeds. The female infructescence contains 200-300 fruit, and fruit set is 50-70%. Fruit ripen about 5-6 months after pollination.

Individual oil palm fruit are drupes with an oily, fibrous mesocarp.
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GENERAL CULTURE
Soils and Climate
    Soil - wide range of soil types, provided good drainage and pH between 4 and 7; tolerates periodic flooding or a high water table; many soils are alluvial in nature. Irrigation is generally not practiced.
    Climate - hot, wet tropical lowlands, major production regions receive at least 6 ft of rain per year, evenly distributed, with at least 4" per month if a short dry season exists; optimal temperatures are in the 80s-90s °F, with temperatures below 75°F slowing growth; 5-7 hr of direct sunlight per day is beneficial.

Propagation
    Oil palm is propagated by seed, using F1 hybrid seed from controlled crosses that produce tenera types (dura x pisifera). Seed is produced by companies specializing  in oil palm breeding.
20.9 
An oil palm planting where older trees have been killed to make way for younger, smaller trees (left). Pregerminated oil palm seeds are sold by companies that specialize in hybrid seed production (right).

Rootstocks - None

Planting Design, Training, Pruning
Optimal plant density is 58 trees/acre with triangular patterns about 30 ft apart. During the first 3 years, little or no fruit is obtained and plantations are often intercropped with staple crops.
Pruning and Training - none, old leaves are pruned off to facilitate access to the bunch at harvest. When palms reach heights of 20-30 ft, they become difficult to harvest, and are often injected with an herbicide to kill them or bulldozed down. New trees are planted among the dead and rotting trunks.

HARVEST, POSTHARVEST HANDLING

Maturity
    As fruit ripen, they change from black (or green in virescens types) to orange, but have varying degrees of black cheek color depending on light exposure and cultivar. However, fruit abscission is the best index of bunch ripeness.

Harvest Method
    Fruit bunches are harvested using chisels or hooked knives attached to long poles. Each tree must be visited every 10-15 days as bunches ripen throughout the year.

Postharvest Handling
   Oil extraction is a complex process, carried out by large mills that may process up to 60 tons of fruit per hour, or by small scale mills in rural villages that produce only about 1 ton of oil in an 8 hour shift. Oil extraction from fruit follows the same basic steps in either case:

    1. Steam sterilization of bunches (inactivates lipase enzymes and kills microorganisms that produce free fatty acids, reducing oil quality)
    2. Stripping fruit from bunches
    3. Crushing, digestion, and heating of the fruit
    4. Oil extraction from macerated fruit (hydraulic pressing)
    5. Palm oil clarification
    6. Separating fiber from the endocarp
    7. Drying, grading, and cracking of the endocarp
    8. Separating the endocarp from the kernel
    9. Kernel drying and packing
  
    The product of step 5 is termed crude palm oil, which must be refined to remove pigments, free fatty acids, and phospholipids, and to deodorize it. The final product, termed "refined, bleached, deodorized" palm oil is produced.
   




Palm oil processing. Bunches are transported to the mill and weighed (top left). Bunches are first steam sterilized in large tanks to inactivate enzymes (top right). Below, palm oil extraction by hand in a village in Nigeria. Fruit are smashed in a hollowed out tree stump and resulting pulp is boiled to remove excess water, and the oil is strained from the fibrous pulp (bottom).

Storage
    Palm oil is stored in large steel tanks at 88-105°F to keep it in liquid form during bulk transport. The tank headspace is often flushed with CO2 to prevent oxidation. Higher temperatures are used during filling and draining tanks. Maximum storage time is about 6 months at 88°F.
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CONTRIBUTION TO DIET

    About 90% of the palm oil produced finds its way into food products, with industrial uses accounting for the remaining 10%. Palm oils are used in a wide variety of foods, primarily margarine, shortening, and vegetable cooking oil. Palm oil is used as a replacement for cocoa butter and butter fat, and in ice cream and mayonnaise. It is stable at the temperatures used in deep frying, and is used quite often for fried foods. Per capita consumption of palm oil specifically is unknown, but Americans consumed 84.7 lbs of fats and oils in 2004. About 45% of this is margarine and shortening, two major products containing palm oil.

Dietary value, per 100 gram edible portion

Oil palm fruit Palm oil
Water (%) 26
 0.5
Calories
540
 878
Protein (%) 1.9
 0
Fat (%)
58.4
 99.1
Carbohydrates (%) 12.5
 0.4
Crude Fiber (%)   3.2
 0

% of US RDA*
Vitamin A
3.5
 2.3
Thiamin, B1 13.3
 2.0
Riboflavin, B2 5.6
 Trace
Niacin 7.0
 ---
Vitamin C
26.7
 ---
Calcium 10.3
 0.9
Phosphorus 5.9
 1.0
Iron 45
 55
Sodium 2.4
 ---
Potassium 5.3
 ---
* Percent of recommended daily allowance set by FDA, assuming a 154 lb male adult, 2700 calories per day.

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