The fruit and its volatiles
Cocos nucifera is a large palm, growing up to 30 meters (100 feet) tall. Its pinnate leaves are 4-6 m (13-20 ft) long and its pinnae 60-90 centimeters (2-3 ft) long; old leaves break away cleanly, leaving the trunk smooth. The palm is intolerant to cold and prefers copious precipitation and full sunlight.
Raw coconut meat is 47% water, 33% fat, 15% carbohydrates and 3% protein. A 100-gram portion of raw flesh supplies 350 calories of food energy. Saturated fatty acids make up 30% of its total fats, and lauric acid is the main one.
Fresh coconut meat has a fruity odor that chromatograms traced to some esters, ketones, aldehydes and alcohols. The oily odor of fresh coconut meat was attributed to a minimal amount of delta lactones. Freshly desiccated coconut contained the same volatiles, but its concentration of delta lactones was considerably higher. In irradiated desiccated coconut, the newly treated product held the highest concentration of delta lactones, together with ethyl caproate, 1-hexanol and caprylic aldehyde.
Production and uses
In 2024, world production of coconuts in shells was 65.5 million tonnes, led by Indonesia, India and the Philippines. In 2024, Indonesia produced 18.0 million tonnes of coconuts in shell, India 14.7, the Philippines 14.5, Brazil 3.2 and Sri Lanka 1.8. Four southern states of India account for most of its production: Tamil Nadu, Karnataka, Kerala and Andhra Pradesh. Kerala has the largest number of coconut trees, but Tamil Nadu is the most productive per hectare.
In 2023, world production of processed coconut oil was 3.1 million tonnes, led by the Philippines with 38% of the total. Indonesia and India are the secondary producers of coconut oil. Coconut oil is used in cooking, especially for frying. It can be used in liquid form like other vegetable oils, or in solid form like butter or lard. The husk and shells of the palm can be used for fuel or made into charcoal, and the husks can serve as flotation devices or as an abrasive.
Coconut oil, copra, milk and water
Coconut oil is an edible oil derived from the meat of the coconut palm fruit. It is a white solid fat below around 25 °C and a clear thin liquid at higher temperatures, and unrefined varieties have a distinct coconut aroma. Beyond the kitchen, it is used in industrial applications for cosmetics and detergent production.
Copra is the dried, white flesh of the coconut from which the oil is extracted. It can be made by smoke drying, sun drying or kiln drying, and it is then pressed or dissolved with solvents. The oil from copra is rich in lauric acid. About a thousand mature coconuts yield around 170 kg of copra, from which around 70 litres of oil can be extracted. Virgin coconut oil can instead be produced from fresh coconut milk, meat or residue.
Coconut milk is traditionally made by grating the white inner flesh of mature coconuts and mixing the shredded pulp with a small amount of hot water. Coconut water is a different thing: it is the clear liquid inside young coconuts, and it is also used to make nata de coco, a jelly-like food.
The lactones
Gamma-nonalactone is an organic compound with the formula C₉H₁₆O₂ and the IUPAC name 5-pentyloxolan-2-one. It is a weakly volatile liquid that is colorless when pure, but typical samples are not. It is one of several gamma lactones, most of which have fruity scents and several of which are used commercially. It is also named gamma-nonanolactone or 4-nonanolide. It is soluble in alcohol, most fixed oils and propylene glycol, and insoluble in water. Its density is 0.958-0.966 at 25 °C. It is combustible, and when heated to decomposition it emits acrid smoke and irritating fumes.
Delta-decalactone is a chemical compound classified as a lactone, with the formula C₁₀H₁₈O₂. Its preferred IUPAC name is 6-pentyloxan-2-one, and it is also called 5-decanolide or delta-pentyl-delta-valerolactone. It occurs naturally in traces in fruit and milk products. It has applications in the food, polymer and agricultural industries. Its density is 0.954 g/cm³, and it is very soluble in alcohol and propylene glycol but insoluble in water.
The prefix of a lactone gives the size of its ring: a gamma-lactone has a 5-membered ring and a delta-lactone a 6-membered ring. The name lactone derives from lactide, a ring compound formed by dehydrating lactic acid, which in turn is named for its isolation from soured milk. The name was coined in 1844 by the French chemist Théophile-Jules Pelouze. Gamma-lactones are so stable that 4-hydroxy acids cyclize into them spontaneously.
