Macadamia Nut Industry in South Africa
The South African macadamia industry is export-based, with over 95% of annual production shipped to international markets. From 2011 to 2013, South Africa was number one in macadamia nut exports in the world. The country exported 21696 tons of macadamia nuts in 2013, commanding 37.1% share of the world exports, while Australia ranked second with 26% share. The Far East– China, Japan, Vietnam – is the largest market, followed by the USA and Europe. In 2013, Hong Kong, China is the major export market with 38.1% share, followed by the United States of America with 24.5 %, the Netherlands with 9% and Viet Nam with 7.3% share. However, this year in 2015, due to the crackdown in China, most of South Africa’s macadamia harvest will have to find other markets.
South Africa Macadamia Nuts Information
South Africa remains the world’s largest macadamia nut producer, having produced 44890 tons of nut-in-shell(1.5% kernel moisture) in 2014, while Australia(where they originated) ranked second. The market is split nearly evenly between kernel exports and nut in the shell (NIS). The Macadamia tree belongs to the family Proteaceae. Only two of the species(Macadamia integrifolia and Macadamia tetraphylla)are edible. Hybrids between these two species are also commercially cultivated. Macadamias were introduced into South Africa in the 1960’s. The main growing areas are Limpopo Province(Levubu and Tzaneen), Mpumalanga Province (Hazyview and Nelspruit), and coastal KwaZulu-Natal.
South Africa Macadamia Nuts Processing
The market value chain for macadamia nuts can be broken down into the following levels: farmers/producers, processing/cracking factory (who dry, crack (dehusk), sort, cook, roast, grade, package, store and distribute macadamia nuts). The factories also sell the nuts to fresh product markets, wholesalers, supermarkets, retailers and informal markets and finally to consumers. About 450 farmers are involved in growing macadamia nuts, supplying up to 10 macadamia nuts cracking factories. The main domestic buyers are Spar, Pick ‘n Pay and Woolworths.
● Macadamia harvesting
Macadamia trees can produce nuts for 40 years. It costs about R100 000/ha to establish an orchard. Farmers have to wait seven years before getting a return on investment. But the rewards are worthwhile.
The harvesting and processing season of Macadamia nuts runs from February to August. The nuts drop from trees when they are mature and are typically collected by hand from the ground.
● Macadamia dehusking
After harvesting, the fibrous outer husk covering the nut is removed by a mechanical de-husker within 24 hours to prevent deterioration. The husks are usually recycled as organic mulch.
● Macadamia nuts drying
At harvest, the macadamia nuts can have a moisture content of up to 30% and shall be dried down to a kernel moisture content of about 1.5%. This is a crucial process to maximize product quality and shelf life. The kernel shrinks away from the shell, allowing the shells to be cracked without damaging the kernel.
Most South African macadamia farmers use in-shed, Bungay style systems for drying macadamia nut in shells. The drying system is totally enclosed within a shed. The nuts in shell are put into the storage bins in the system. Pre-heated air from the electric heater or the roof space is circulated through the nuts, achieving the aim of drying. The Bungay style system has a significant reduction in energy consumption, which results in significant savings.
● Macadamias nuts cracking Shelling process
Macadamia nuts have an extremely hard shell that cannot be open with a regular nutcracker, and may even break the cracker. Cracking of the shell is done mechanically by a specially designed macadamia nuts cracking machine. Nuts are cracked between a rotating steel roller and a fixed plate. The distance between the roller and the plate of the macadamia nut cracking machine can be adjusted for the different size of nuts.
The crack-out rate (the percentage of edible kernel retrieved from the nut) depends on the variety and the moisture content of the nut when cracked. The average crack-out rate in South Africa is 27,6%. This means 72.4% of the weight of the nut in the shell is waste in the form of shells.
After cracking, the shells are separated from the kernels by kernel-shell separating machine, followed by a final hand sorting to remove poor quality kernel. Then the kernels are graded by a rotating screen into different styles, ranging from Style 0, which are minimum 95% wholes used in high-quality snack products, to Style 8, which are fines smaller than 3mm.
The kernels then may be roasted, salted or simply packaged raw.
EU and US is the traditional market for cracked nuts for both the snack and ingredient market, while China buys uncracked nuts (NIS) and roast it inside as a snack.
● Macadamia kernels packaging
The macadamia kernel deteriorates rapidly and requires a storage environment that is very low in moisture and oxygen. This is best achieved by a combination of gas flushing with carbon dioxide or nitrogen and partial vacuuming before sealing the pouch. The sealed pouch is packed into cartons, most commonly of net weight 25lbs (11.34kg) per carton.
● Macadamia kernels storage
Vacuum packed raw macadamia kernel should be stored in a cool (15°C to 25°C), dry and well-ventilated area. Provided the correct vacuum pouch material, with the oxygen and water vapor transmission rate properties is used, the kernel will maintain its quality for 16 to 18 months. For longer shelf life, the product should be stored under cold storage with low relative humidity.
Applications of Macadamia Nuts and Kernels
Macadamia nuts are commonly eaten as a snack with shells. Usually, unshelled macadamia nuts are sawn by macadamia nuts sawing/cutting machine and making a slot can make flavors infiltrate into nuts when frying and make it easy to remove the shells when eating.
Shelled macadamia nuts are widely used as ingredients in confectionery, baking and ice cream industries. The kernels can also be processed to produce an edible oil. The remaining oil cake might be used for animal feed. Macadamia oil has a high smoke point, and is ideal for stir-frying, sautéing and salad dressings. The oil contains 80% healthy monounsaturated fat, the highest percentage amongst cooking oils, which can help reduce bad cholesterol. Macadamia oil is also used in cosmetics to treat dry skin. Macadamia shells can be used as mulch or burned to generate heat. Husks are used as mulch or composted for fertilizer.