Less work for better returns: macadamia sorting system is an all-round cracker

Better returns, reduced loss, improved product quality and a high throughput rate: the new dehusking and sorting system at the Macadamia Processing Company’s (MPC’s) Alphadale facility has been a success for growers and processors alike.

“Since the 1990s, the macadamia industry has approached quality by applying reject penalties in payment systems,” said MPC’s General Manager, Steve Lee. “This has caused farmers to spend many hours sorting and resorting macadamias on their farm before delivery to the factory. It’s a costly process for growers and we felt there had to be a better way.”

MPC's new sorting system has led to better quality product.

“So we set about developing a system that removes the need for farmers to sort their own nuts, increases yield per hectare, reduces potential quality losses and maintains the value of the macadamias.”

“We also wanted to centralise the task of dehusking and sorting nuts without slowing down the current rates of receiving and processing,” added Kevin Quinlan, Supply Chain Manager - NIS (Nut-In-Shell) at MPC. “This meant we needed machinery with high throughput rate that was highly efficient and could be operated with minimal supervision by staff.”

MPC wanted a system that was at the cutting edge of macadamia processing with new cleaning technology, combined with the latest NIS and kernel colour sorting machines. It had to be efficient and able to handle high volumes while handling the macadamias in such a way as to minimise damage.

“There were some challenges because this is a first for the industry,” Quinlan said. “It was not just a matter of installing existing equipment.”

MPC’s Alphadale facility.

MPC devised a solution based on a mix of standard machinery and specifically designed machinery to meet its needs.

“Some of the new machinery is available commercially and we used that where appropriate,” Quinlan said. “However, we had to design some of our own equipment as there is not much macadamia-specific machinery available commercially anywhere in the world. Some of the standard equipment had to be modified in terms of its operating parameters, both physical and programming, especially for the new colour sorters.”

All design work was carried out in-house, with MPC’s engineering staff drawing on past experience to design and manufacture a system that would suit the company’s needs.

In researching the new system, MPC found that by reducing the interval between nut fall and delivery to the factory, growers’ returns would be improved as quality would be maintained. Not having to store nuts for sorting reduces the possibility of storage defects like discolouration, mould and internal discolouration (brown centres).

The new cleaning machinery removes trash, rock and rejects from consignments before they are sampled and placed in silos. This service is provided free of charge to MPC’s growers. When combined with the kernel colour sorters, MPC is now able to remove all rejects that were formerly removed by on-farm hand sorting.

For growers requiring full dehusking, MPC has worked with Alstonville’s House With No Steps to develop a system that offers full dehusking at a cost of 6 cents per kilogram of input weight.

“The new system is allowing us to operate at our same receiving and processing speeds,” Quinlan said. “For our growers, they are experiencing a reduced workload and considerable cost savings, often up to 10 cents per kilogram.

“From our perspective we are seeing good quality nuts reaching the factory and our processing speed has been maintained. Most importantly, consumers will get to taste the higher quality kernel produced from our changes and we believe this will see increased demand for our products,” Quinlan said.

“We see the new system as a win for both the grower and the consumer,” Lee added.