Macadamia Nut processing
Ripe macadamia nuts fall to the ground where they are picked up for processing.
Picking
Once picked the outer husk of the macadamia is removed with a mechanical dehusker. The nuts are loaded into a hopper which feeds the nuts through two rotating rollers. The rollers rip off the tough outer husk from the raw brown shell of the nut. The nut in shell that emerges weighs only around 46% of the nut in husk and has a moisture content of approximately 20%. The left over husks are composted and used as mulch.
Drying
Macadamia nuts in their shell need to have plenty of air. The nuts are stored in this in a silo where they remain fresh as well as drying the nut down. This shrinks the kernel away from the inside of the shell to avoid damaging the kernel when cracking takes place.
Sorted
After leaving the dryer, the nuts are fed into a rotating cylindrical sorter prior to cracking. As they pass along the trommel the nuts are sorted into sizes by a series of progressively bigger holes which allow the nuts to fall through into their appropriate bins. This sorting allows the mechanical cracker to be placed on an appropriate setting according to the size of the nuts being cracked.
Separated
The nuts are then sorted by a water flotation method that separates cracked shell from kernel. This works on the principle that first grade kernel floats whereas poor quality kernel and shell sinks. The first grade kernel is then passed through a drying oven and through a colour sorter which separates out any remaining pieces of shell. The kernel then goes along the inspection bench for a final manual inspection before being sized and stored.
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