School Science Lessons
Coconut Project
Updated: 2008-12-14
Please send comments to: J.Elfick@uq.edu.au
See: Interesting websites, coconuts
17.0 New ways to make coconut oil
The industrial production of coconut oil starts with the pressing of heated copra. The product of this process contains a high level of free fatty acids and undesirable flavours, colours and aromas because of the variable quality of copra from different sources. Before edible coconut oil can be produced, further processes of refining, bleaching and deodorizing are needed. By contrast, virgin coconut oil made from the fresh kernel without heating is edible if the extraction is done properly. This oil is stable with a long shelf life, has a low content of free fatty acids and provides Vitamin E in the diet.
New technology allows coconut oil to be made locally where the coconut palms grow. New methods are being used to make "virgin coconut oil", i.e. coconut oil pressed without using long high temperatures, up to 60oC. Virgin coconut oil is derived from fresh coconuts not copra. With the wet-milling method the oil is extracted from fresh coconut meat (kernel, endosperm) without drying first. Coconut milk is expressed first by pressing. The oil can then be separated from the water by boiling, fermentation, refrigeration, enzymes and centrifuges. Virgin coconut oil has a neutral colour and attractive aroma of a distinctly coconut flavour but not the roasted flavour of traditional village coconut oil. Virgin oils made by methods 1. and 2. below have stimulated a market in developed countries for coconut oil as a medicine (neutriceutical, health-assisting food) to be processed to soaps, shampoos and body lotions, and to be used in deep frying, cakes and biscuits. The advertising for virgin coconut oil highlight its health benefits, e.g. assisting in weight loss and boosting body energy. The old technology used to extract oil from copra produced low quality "industrial" oil produced by using very high temperature and pressure in a factory. This oil required refining, bleaching and deodorizing before it could be used in food preparation or for high quality soap. There is no world standard definition of virgin coconut oil
1. Fermentation and gentle heat method
Stand the coconut cream at room temperature for 24 to 48 hours to cause separation of water from the emulsion. Pour off the now concentrated emulsion and heat gently to drive off any remaining water. The settled oil is clear, colourless and has an attractive aroma. They market it as virgin coconut oil. This oil does not undergo the prolonged boiling used to produce village oil from coconut cream. The protein in the coconut cream breaks down during the standing period. However, the village method of boiling fresh coconut cream causes coagulation of the protein, which becomes roasted as the boiling proceeds and gives a distinct flavour to the oil. Coconut oil produced by the prolonged boiling method may have free fatty acids of 1% owing to the high temperature experienced in the final stage of heating, but coconut oil separated by the fermentation method has lower free fatty acids content and fetches a premium price.
2. Direct microexpelling method (DME)
In the direct micro expelling method of wet-milling the oil is extracted from fresh coconut meat (kernel, endosperm) after the adjustment of the water content, then the pressing of the coconut flesh results in the direct extraction of free-flowing oil. This process extracts coconut oil under moderate pressure and temperature, generally not above 60oC, from shredded coconut at moisture content about 11%. The process achieves up to 90% extraction of the oil. The raw meat (kernel, endosperm) is shredded finely by a powered rotating head. Shredding with a traditional tool is too slow and the shreds are too coarse. The shredded coconut is quickly dried on a large iron plate then packed tightly into a perforated cylinder. The coconut is squeezed by a piston pushed down into the cylinder under pressure from a lever mechanism operated by hand. The press can produce up to 1 litre of oil per batch. Four operators can produce about 50L per day from about 500 coconuts, depending on the amount of meat (kernel, endosperm) per coconut. After the oil is extracted, the remaining residual cake can be used in the kitchen for baked products or as supplemental feed for pigs and poultry. The DME oil has outstanding qualities of aroma and clarity after a settling time of two days. It is stable and appears to have an indefinite shelf life without developing free fatty acids at room temperature.
3. Fry-drying method or Hot Oil Immersion Drying method (HOID)
This method is based on a traditional method of producing coconut oil for local markets in south-east Asia. It uses a hot coconut oil bath to dry fresh coconut meat (kernel, endosperm) from which, after draining, the oil is pressed out using a high pressure screw press after mincing the dried pieces. The acceptable shelf life for the oil produced is 2 to 3 months. Fry-drying is recommended at a regional scale with access to 250 ha of productive palms per factory for commercial success. Equipment to process 2 tonnes of meat (kernel, endosperm) per day would have a daily output of about 700L of oil. Fry-drying oil has a roasted flavour, which appeals strongly to the domestic market for cooking oil but the price is much lower than for DME and fermentation oil.
19.0 Intercropping
Coconuts are almost the ideal plant for inter-cropping because of the low percentage of air space between canopy and ground of older palms, the structure of  the canopy fronds and the percentage of solar radiation they allow to pass, and  the radius and depth of the roots. At the common planting distance of 8 X 8 meters only about 25% of the plantation area is used by the roots and most roots are between 30 and 130 cm depth. Also only about 45% of the radiation from the sun falls on the coconut palm leaves. So coconut growing is an inefficient way to use land! Other crops can be 12 times more efficient. The annual crops corn (maize) soybean, peanuts and sweet potato have about 40% yields under coconuts compared to growing in the open. Mung bean, sweet pepper, Tabasco pepper, sunflower, ginger and taro may have increased yield under coconuts. Robusta coffee and cocoa can be very successful annual intercrops and many tropical perennial crops have proved successful, e.g. pineapple, papaya, jack fruit. Intercropping may increase the yield of coconut palms if the soil is lightly cultivated. In some place cattle are successfully kept under coconuts. Cattle check weed growth and give manure to the soil but they may also compact the soil. Shade tolerant grasses and legumes may planted e.g. Guinea grass (Panicum) Pangola grass (Digitaria) Centro (Centrosema) Stylo (Stylosanthes) Siratro (Phaseolus) Ipil-ipil (Leucaena). Beside cattle and other animals under coconuts, intercrops can include ornamental plants, Gliricidia for fuel and cattle feed, the tubers cassava, sweet potato,  taro,  yams,  the cereals finger millet, maize (corn) sorghum, the legumes cowpea, green gram, groundnuts (peanut) soybeans (soya beans) winged beans, the fruits banana, citrus, papaya, passionfruit, pineapple, pomegranate, the spices areca nut, betel nut leaves, black pepper, chillies, cinnamon, cloves, ginger, nutmeg, sesame, turmeric, vanilla, and also pasture grasses, cocoa and coffee. However, intercrops may compete for soil nutrients so some special applications of fertilizers may be needed.
21.0 Future of coconut growing
It has been recognised for several decades that the uncritical message that coconut oil boosts harmful cholesterol creating an increased heart risk is not true. The soy industry worked very hard to discredit coconut oil after the second world war when imports to the US resumed following liberation of the Philippines. The wartime boost to demand for edible oils in the US had given the soy industry a huge lift and the producers and marketers were keen not to concede the market back to the prewar preferred coconut shortening and cooking oil. The trials that showed cholesterol to rise in lab animals on sole coconut as the fat component in the diet, compared to steady cholesterol when soy was the sole dietary oil, gave that bad result for coconut as coconut lacks the essential fats omega 6 and omega 3. The animals were suffering from that deficiency and their cholesterol was high. The soy industry siezed upon those results and re-educated a whole generation of health professionals and dietitians about dietary fats along the lines of saturated is bad and polyunsaturated is good for your heart.Without going into more detail in this message, there are many references on the internet that deal with this story. In reality the saturated fats in coconut oil boost HDL as much as they boost LDL so that there is a non-harmful balance maintained. Coconut is definitely not a heart risk in a balanced diet.
 In the Pacific islands large scale commercial plantations is in decline but smallholder production continues because coconuts are important for consumption, cash crops and shade for intercrops in subsistence agriculture. Green coconut water is an important source of fluids and mineral salts for people living on coral atolls and its isotonic properties make it useful for diarrhoea, cholera and other causes of dehydration. Coconut flesh supplements fish in remote communities. As a cash crop, coconuts may be sold locally, processed at village level to make coconut oil, meal and coconut cream but the main cash crop is copra sold to traders and processors. Prices of coconut products are not stable in the world market and cyclones may destroy crops, so coconut farmer need intercrops for income security. In the Pacific islands a big proportions of coconuts may not be picked up for harvest when prices are low because of the cost of labour from outside the family. Average figures for a smallholding of 0.5 hectares in Papua New Guinea have been estimated a nut yield of  3000 kg / hectare, average weigh 1.5 kg per nut, copra yield 0.24 kg / nut, copra yield 480 kg / hectare and total dried copra production of 240 kg. The smallholder has to pay for labour to collect nuts off the ground or harvest from tree, labour for dehusking, drying the endosperm and transport of copra to a trader. When the international copra price is low copra production is attractive only where alternative employment opportunities are limited. In many countries, a high percentage of coconut palms are senile with declining production. Smallholders may be content to allow self-seeding  to maintain stands of trees of different ages instead of replacing palms with high yielding varieties to avoid a declining productivity which may not even be noticed. Where there is insecure land tenure or customary tenure, smallholders may not want to risk cash investment to improve yields. Where governments have been involved in the marketing, finance, regulation, research and advice of the coconut industry run by smallholders,  the fees for such services have acted as a tax on smallholders and limited the use of new technologies to increase production.

2.0 Characteristics of Tall coconuts and Dwarf coconuts
Characteristic Tall coconuts
 Dwarf coconuts
Bearing intervals Continuous, all stages at any time
 May be irregular
Bearing time after planting 5-7 years 3-4 years
Fruit size Small to large Small to medium
Harvesting Difficult if not mechanized Easy
Height, mature height 15-22 metres < 8 metres
Intercropping activities Legumes, fruits, spices, pasture grass, cocoa Grazing cattle
Intercropping potential Higher Lower
Life, productive life <50 years <30 years
Life, to senile age 60-70 years 30-40 years
Life span, death of palm
 80-100 years < 50 years
Logging suitability High Low
Oil content 66-70 % 65 %
Planting density, grid 7-10 metres 5.5 metres
Planting density 160 palms / ha (8 m grid) 330 palms / ha
Pollination Cross-pollinating Self-pollinating
Storm damage Lower risk Higher risk 
Use by smallholders Wide use
 Limited use
Yield, plantation, av. 9,700 nuts / ha 11,000 nuts / ha
Yield, plantation, av. > 150 g copra / nut 90-120 g copra / nut
Yield, plantation, av. 2.8 tons copra / ha 2.9 tons copra / ha
Yield, smallholder 0.8-0.9 tons copra / ha little used
15.1 Fatty acids in coconut oil and other oils
% proportion of edible fatty acids in the oil of natural products
Source
 Caprylic C8
 Capric C10
 Lauric C12
 Myrstic C14
 Palmitic C16
 Stearic C18
 Oleic
C18
 Linoleic C182

 alpha Linoleic C183
Coconut
 08
  7
 49
 18
  8
  2
  6
  2
 .
Soy
 .
 .
 .
 .
 11
  4
 23
 53
  8
Maize
 .
 .
 .
 .
 12  2
 28
 57
  1
eanut
 .
 .
 .
 .
 12
  5
 46
 31
 .
Butter
  1
  2
  3
12
 16
 12
 45
 10
  1
Trivial name, systemic name
Caprylic acid, octanoic acid, CH3(CH2)6COOH saturated fatty acid
Capric acid, decanoic acid, CH3(CH2)8COOH saturated fatty acid
Lauric acid, dodecanoic acid, CH3(CH2)10COOH saturated fatty acid
Myrstic acid, tetradecanoic acid, CH3(CH3)12COOH saturated fatty acid
Palmitic acid, hexadecanoic acid, CH3(CH2)14COOH saturated fatty acid
Stearic acid, octadecanoic acid, CH3(CH2)16COOH saturated fatty acid
Oleic acid, cis-octadec-9-enoic acid, cis-09-octodecanoic acid, CH3(CH2)7CH=CH(CH2)7COOH mono-unsaturated fatty acid
Linoleic acid, CH3(CH2)4CH=CHCH2CH=CH(CH2)7COOH polyunsaturated fatty acid
alpha Linoleic acid CH3(CH2)CH=CH(CH2)CH=CH(CH2)CH=CH(CH2)7COOH polyunsaturated fatty acid
The melting point of unrefined coconut oil melts is about 25oC and the smoke point is 170oC, but 232oC if refined. Coconut oil is a comparatively stable oil that oxidizes slowly and becomes rancid slowly because of the high saturated fatty acid content. However, for long periods it should be stored solid below 25oC.
18.0 Summary of the coconut palm structure
18.1 Roots
embryo --> radicle (dies) cotyledon sheath --> adventitious roots main roots, primary roots root = root cap, root tip + absorbing hypodermis + red impervious hypodermis

trunk -->		 bole, swollen base of stem internodes --> adventitious roots main roots, primary roots root = root cap, root tip + absorbing hypodermis + red impervious hypodermis

trunk -->		 bole, swollen base of stem internodes --> adventitious roots lateral roots, main root branches --> rootlets root = root cap, root tip + absorbing hypodermis + red impervious hypodermis

trunk -->		 bole, swollen base of stem internodes --> adventitious roots lateral roots --> air breathing roots, pneumathodes, whitish lumps
18.2 Stems, trunks
single growing point, growing bud, central bud, main bud, vegetative bud, terminal bud, terminal meristem, apical bud, "cabbage" tip of old stem narrows to "pencil point"
trunk --> leaf scars
trunk --> leaf axils (where the leaf meets the stem)
trunk --> monocotyledon series of joints "node + leaf + internode" up the stem, internodes very short
bole, swollen base of stem --> roots .
18.3 Leaves, fronds
All leaves from a leaf crown
cotyledon --> first green leaf seedling leaf and all leaves at first entire, fused leaflets, in fibrous leaf sheath, spear ---> leaf or frond, sword leaf, in terminal crown
leaflets, pinnae 1. lamina leaf or frond, sword leaf, in terminal crown
midrib, rachis 1. lamina leaf or frond, sword leaf, in terminal crown
-. 2. leaf stalk, petiole leaf or frond, sword leaf, in terminal crown

-		 3. leaf base + fibrous sheath leaf or frond, sword leaf, in terminal crown
18.4 Inflorescence, flowers
Monoecious, male and female flowers
male flowers (200 to 300) P 3+3, A 3 + 3 inflorescence, flower bunch, flower cluster spadix inflorescence in axil of each leaf, 1-2 metres long
female flowers (20 to 50) P3 + 3, G1 inflorescence, flower bunch, flower cluster spadix inflorescence in axil of each leaf, 1-2 metres long
main axis, main stalk, peduncle --> rachis --> lateral branches, spadix branch, flower stem --> flowers inflorescence, flower bunch, flower cluster spadix inflorescence in axil of each leaf, 1-2 metres long
lateral branches inflorescence, flower bunch, flower cluster spadix inflorescence in axil of each leaf, 1-2 metres long
outer sheath of spathe sterile spathe, bract enclosing inflorescence, 1- 5 metres long spadix inflorescence in axil of each leaf, 1-2 metres long
inner sheath of spathe fertile spathe, bract enclosing inflorescence spadix inflorescence in axil of each leaf, 1-2 metres long
18.5 Seed and fruit
exocarp, rind, smooth skin . . fruit, seednut, fibrous drupe, button coconut
mesocarp, fibre and pith, husk (coir) . . fruit, seednut, fibrous drupe, button coconut
endocarp, hard shell, . "nut", round coconut, dehusked coconut fruit, seednut, fibrous drupe, button coconut
embryo seed "nut", round coconut, dehusked coconut fruit, seednut, fibrous drupe, button coconut
testa, brown seed coat seed "nut", round coconut, dehusked coconut fruit, seednut, fibrous drupe, button coconut
meat (kernel, endosperm)
white flesh		 seed "nut", round coconut, dehusked coconut fruit, seednut, fibrous drupe, button coconut
cotyledon --> haustorium, button, apple, egg seed "nut", round coconut, dehusked coconut fruit, seednut, fibrous drupe, button coconut
coconut water, coconut water, liquid endosperm,
"coconut milk"		 seed "nut", round coconut, dehusked coconut fruit, seednut, fibrous drupe, button coconut