Chemistry of Coconut
✿ The coconut tree is considered as a great gift of Nature to mankind
, especially in the tropical Asian Pacific countries where people have been reaping its benefits throughout the ages.
What is so special about the Coconut tree is that almost all parts of the tree are utilized by humans for their basic needs – food, shelter and medicine.
✿ In Sri Lanka, it is traditionally used in religious ceremonies, in cultural events and festivals. Coconut oil is used as a fuel to light lamps by dipping a wick in the oil. The young leaves or fronds are used as decoration for festivals, and the inflorescence ('flower') is used in cultural ceremonies, at traditional weddings to bring good luck to the couple.
✿ Many health benefits are attributed to the unique composition
of the oil obtained from the coconut kernel.
✿ Coconut oil is a liquid at temperatures around 25C and above. Refined coconut oil is almost colourless whereas crude unrefined oil is a golden yellow. It has a long shelf life, stable to atmospheric oxidation, due to its low degree of unsaturation
✿ More than 90% of fat in coconut is saturated fat
. Therefore it has earned a bad image as being an oil which is harmful to health, since saturated fats are known to contribute to cardiovascular disease. However, this same property of high saturation is responsible for its health benefits, because the saturated fats that are present in coconut are made up of mostly Medium Chain Fatty Acids (MCFA)
rather than Long Chain Fatty Acids.
✿ What are saturated medium chain fatty acids
Carboxylic acids having 8 to 10 carbon atoms, without any double bonds between carbon atoms are known as saturated medium chain fatty acids. The MCFA in coconut oil are Caprylic acid, Capric acid and Lauric acid
Coconut oil has more MCFA than other vegetable oils
such as olive oil, soyabean oil, palm oil, groundnut oil and sunflower oil.
✿ Of the MCFA, Lauric acid is the major component, (48.9%) in coconut oil. Monolaurin
, a derivative of lauric acid has antibacterial properties and is used in food and cosmetics.
✿Coconut oil is extracted from the kernel of the coconut. Commercial method is by mechanical extraction from copra (dried kernel)
. Domestic extraction is mostly by boiling coconut milk
(water extract of kernel) and separating the oil.
We come across two main types of coconut oil in the market, based on its processing. RBD coconut oil
is “Refined, Bleached and Deodorized
” The other type is Virgin Coconut oil
which is made by wet processing, without any drastic heat treatment as with the other types of extraction.
✿ Coconut oil is used in margarine manufacture
by blending with other vegetable oils and by the chemical modification of its components. The melting point of vegetable oils is raised by a process called hydrogenation
, or 'hardening' resulting in a semisolid product. http://en.wikipedia.org/wiki/Margarine
✿ Hydrogenation converts unsaturated fatty acids in the oil to saturated fatty acids thereby elevating the melting point of the oil. Partial hydrogenation results in the formation of trans fatty acids
by altering the natural configuration of some of the unsaturated fatty acids in the oil. The negative aspect of the process of hardening oils to semisolid fats is the formation of trans fats
. Trans fats are known to increase the risk of cardiovascular disease. However, coconut oil has a very low chance of producing trans fatty acids
than some other vegetable oils, e.g. sunflower oil and canola oil, which contain poly unsaturated fatty acids (PUFA)
. This is because coconut oil has a lower amount of unsaturated fatty acids (the components that produce trans fats when partially hydrogenated).
✿ Another important industrial application of coconut oil is in the production of biodiesel
. The process involves a method known as transesterification
which converts the oil (esters of glycerol) into methyl or ethyl esters of the fatty acids (‘biodiesel’). http://ljs.academicdirect.org/A16/095_104.htm
✿ Coconut water
too has many uses. It is consumed as a beverage, the water of the King Coconut
being a refreshing drink in the hot weather of the tropics. It is used as a re hydrating drink
due to its unique balance of electrolytes.
✿The inflorescence of the coconut tree contains a sap which is rich in sugars. The sap is collected and allowed to ferment resulting in an alcoholic beverage - Toddy
. The fermented sap is distilled to produce Arrack
, a spirit with a taste usually described as "somewhere between whisky and rum". It is generally distilled to between 33% and 50% alcohol by volume (ABV) or 66 to 100 proof). http://en.wikipedia.org/wiki/Arrack
✿The fermented sap from the inflorescence is used to produce coconut vinegar
. Under aerobic conditions the ethanol in Toddy is converted to acetic acid
by Acetobactor spp
(acetic acid bacteria).
✿ Coconut shells
are used to produce charcoal
which is used in industry as an adsorbant
. In this process shells are burned in a limited supply of air and are carbonized. (Destructive distillation)
Shells contain lignin (29.4%), Cellulose (26.6%) Pentosans (27.7%), which break down at high temperatures, yielding charcoal, pyroligneous acid, tar and gas. Compared to hardwoods, coconut shells are lower in cellulose, higher in lignin.
✿ A great gift of Nature to mankind, the coconut tree is unique in its composition.
Knowing the chemistry of its component parts and the application of chemistry in its utilization makes us appreciate the coconut tree more and more as the Tree of Life
Useful link for chemistry of coconut oil: http://coconutboard.nic.in/English-Article-Gopalakrishna-CFTRI.pdf #sciencesunday #scienceeveryday