16/12/2021 | South Africa

South African nut producer enhances product quality with sorters by TOMRA

20 years ago, a group of South African macadamia farmers decided to collaborate in processing and marketing their crops themselves. Today this group is called Golden Macadamias, and is one of the global leaders of the nut industry.

Investment in the new TOMRA 5C premium optical sorting machine, designed for nut and dried fruit applications, enabled Golden Macadamias to achieve the high product quality. When combined with TOMRA's Biometric Signature Identification (BSI) scanning technology, this machine can detect and eject product defects that cannot see any other technology. 


The South African macadamia industry contributes 20% - 25% of the world's macadamias, which makes it one of the largest contributors, along with Australia, Kenya, and China.  

According to Norman Smith, Area Sales Manager Africa, TOMRA Food, at present, 98% of the macadamia crop is exported. Around 55% of South Africa's macadamias are sold to the kernel market, mostly for export to the U.S., Asia and Europe. The other 45% is destined to the in-shell market, some for domestic sale but mostly for export to China. The kernel market demands the highest product quality.  

The 21.000 square-foot production facility of Golden Macadamias is located in the northeast of the country, next to the city of Mbombela. This area is enriched by fertile soils and a subtropical climate with cool and dry winters, ideal for growing sugarcane, citrus and tropical fruits, and nuts. 


Macadamia nuts are harvested when they naturally fall to the ground. Then it is necessary to remove the green outer husks to sort the nuts and remove defective products and foreign materials. After this, the nuts are graded by size. Because 2/3 of each nut comprises a shell, processors have to work with an extremely high defect level after cracking the nuts. Significant quantities of shell must be removed to clean up the kernel. 

Some macadamia sorting is still done manually, which is not the most reliable and effective way. 

To minimize drawbacks, Golden Macadamias complements the sorting tasks that are done by hand with machine sorting. Automated sorters can assess nuts accurately, consistently, and at remarkable speed for hours, without compromising efficiency, unlike manual sorting. Moreover, mechanical sorters can detect and eject the majority of in-shell defects invisible to the human eye. Product quality is enhanced through the automated capabilities, food waste is minimized, yield is improved, and throughput is high. 

After the nuts are cracked and before they are manually graded, Golden Macadamias utilizes TOMRA's BSI technology.


After having witnessed the results performed by the Nimbus BSI+, the company decided to continue developing its partnership with TOMRA by acquiring 10 TOMRA 3C machines and TOMRA 5C with BSI+ technology.

According to Peter Edmondson, General Manager at Golden Macadamias, their partnership with TOMRA has proved strong throughout many years.

The TOMRA 3C eliminates foreign materials (stones, shells, sticks, etc.) and, depending on the sorting process, can achieve up to 99.5% purity. It also can separate the shell from the kernel with a low giveaway. This machine can do all this while sorting over 20 tons of nuts per hour. The TOMRA 3C can also be utilized in a second position on the line to remove discolorations, moldy and rotten kernel, or any remaining shell. 

According to Norman Smith, TOMRA's unique BSI+ technology scans materials with both near-infrared (NIR) and visible spectrum wavelengths, in order to examine nuts both externally and internally. This technology can detect and reject nearly invisible defects in macadamias: early germination; mold; cracked, pale, dark or black shells; immature and shriveled nuts, the ‘791 spot' kernel disorder; and insect damage from stink bugs and moths.

Peter Edmondson said that TOMRA's machines handle large volumes well, and they have been impressed by the results delivered by BSI+ technology. After cracking and before manual grading, they have been able to decrease the level of unsound nuts from 8 to just 4 percent. 

All these results convinced Golden Macadamias to acquire the TOMRA 5C, the latest platform to utilize BSI+ technology. This premium optical sorter can be also linked to the cloud-based data platform TOMRA Insight, which gathers and stores data from sorting machines.


TOMRA Food is a producer of sensor-based sorting machines and integrated post-harvest equipment for the food industry. The company uses one of the world’s most advanced grading, sorting, peeling and analytical technology.

Their main goal is to help their customers to improve returns, gain operational efficiencies, minimise food waste, ensure quality and a safe food supply with sustainable technologies. 


Their solutions are installed at food growers, packers and processors around the world. This allows businesses to maximise productivity and recovery rates, while reducing food waste and developing the overall quality of the produce.



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