Macadamia Processing Plant & Machinery Solutions

The green husk is removed soon after harvest and immature, light and damaged nuts are taken out of the lot. Husk left sitting on the nut holds moisture against the shell, so it is stripped before drying begins.

Nut-in-shell is dried in stages, moving from ambient air through to warm air, so the kernel shrinks away from the inside of the shell. A kernel that has pulled clear of the shell releases whole when the nut is cracked.

Dried nuts are separated into size bands and fed to the cracker band by band, because the shell is thick and hard and the setting has to match the nut. The output of this stage is a mixture of kernel, half shells and shell grit.

Kernel and shell are separated by density and by air flow, and the shell fraction is collected separately for fuel and other uses. Fine shell dust is drawn off at the same point rather than travelling with the kernel.

Kernels are graded into whole, half and piece styles and sorted by colour, with discoloured and immature kernel removed. Camera and X-ray inspection catch shell that has travelled through with the kernel.

Kernel may be roasted and salted or coated before packing, or packed raw for industrial buyers. Macadamia kernel is high in oil, so vacuum and gas-flushed packs are the usual export formats.