The copra industry of Malaysia started as early as 1940′s. In 1950-51 there were a total of 86 mills, most of which were located in Johor, Penang/ Province Wellesley and Selangor. They consumed about 160,000 metric tones of copra each year and the coconut oil and copra cakes produced were mostly for local consumption. However, the industry began to decline when the shortfall of copra production became more acute after 1977.
Copra Milling Processes
Copra milling has long been practiced in Malaysia. Using the hydraulic expeller, coconut oil can be extracted from copra, giving a minimum oil yield of 60%. Prior to the extraction of the oil, the copra is subjected to various stages of pretreatment, to ensure a high yield of oil. Pretreatment work involves grinding, heat-treatment or cooking and conditioning (moisture control).
To facilitate the subsequent process of oil extraction, the copra is initially passed through a series of grinders such as hammer mills or flakers to reduce the solid material into finer and more uniform mass.
Heat-Treatment or Cooking
Heating the copra meal in a cooker facilitates the coalescing of the oil droplets (which are originally of ultra-microscopic size) into larger droplets. Moreover, increasing the temperature also causes the protein in the copra to break up and form an emulsion, thus favouring the separation of the oil from the solid mass.
Conditioning (Moisture Control)
The ultimate yield of oil during subsequent processing is governed by proper heat treatment as well as optimum moisture conditioning. Heating associated with moisturing produces a film of water on the solid mass, enabling the oil to flow out more readily.
After pretreatment, the copra undergoes various stages of processing and purification.
Hydraulic pressing produces cakes which are round in shape or form and are known as ‘Poonac’. Hydraulic pressed and expeller-pressed oil cakes contain a residual oil content of 8% minimum.