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Macadamia Nutrition

Why should I eat Macadamias?

Macadamias – the world’s finest nuts – are characterised by their crisp texture, delicate flavour, versatility of use and long shelf life. In other words, they are Yummy! Macadamias are  also good for you. Medical research has shown that the consumption of macadamias may significantly lower the risk of heart disease. So replacing some of your saturated fat intake with the mono-unsaturated macadamias could help protect your heart.What is in a Macadamia?Macadamias are rich in macadamia oil, which is very stable and contains high levels of the nutritionally important monounsaturated fatty acids. They contain no cholesterol.

A typical composition is as follows:

Natural oil   75.0 % Protein 9.0 % Carbohydrate  9.3 %
Moisture 1.5 % Mineral Matter  1.6 % Fibre  2.0 %

Macadamia nutrition: The kernel contains Vitamins Al, BI, B2, Niacin and essential elements such as Calcium, Iron, Phosphorus, Magnesium and Potassium.

How does this compare to other nuts and oils?

The table below shows that Macadamia oil contains the world’s highest percentage of monounsaturates, exceeding both olive and canola oil.

Oil Type % Unsaturated Fats % Saturated Fats
Poly Mono
Macadamia Oil 4 84 12
Almond Oil 25 65 10
Animal Frying Oils 5 45 50
Butter 7 36 57
Canola Oil 30 63 7
Olive Oil 10 76 14
Palm Oil 10 39 51
Peanut Oil 36 45 19
Pecan Oil 34 55 11
Safflower Oil 77 14 9
Soyabean Oil 62 23 15
Sunflower Oil 66 23 11
So why are mono-unsaturated fats good for us?A recent study at Wesley Hospital in Brisbane found that a diet enriched by macadamias actually lowers harmful blood cholesterol in participating patients. The research concluded that eating 6-20 macadamia nuts per day actually lowered harmful blood cholesterol by 7% and triglycerides by 25% when compared with a high complex carbohydrate diet.Is cholesterol still considered important?            The discussions and information about cholesterol in the last 10 years have been controversial. However, an increased blood cholesterol level is still considered one of the major risk factors in the development of cardiovascular disease. It is recognised that one of the dietary factors contributing most to an increased blood cholesterol level is the type of dietary fat consumed. A high intake of saturated fat (typical Western diet) contributes to increased blood cholesterol while a higher proportion of monounsaturated and poly-unsaturated fats (such as in Macadamias) appears to protect against cardiovascular disease by lowering total cholesterol and increasing the HDL-cholesterol (good cholesterol).(nutritional information prepared by Ingrid Perols, Dietician and lecturer,

Why are Macadamias good value?

Eating the best tasting products that are best for you is always good value! To look at it another way, if we pick 100 kg of nuts with husk from our trees we will have 46 kg after dehusking, 34.5 kg after drying and only 10 kg of kernel after cracking. Thus we have 90% waste products – the remaining 10% deserves to be good!

Other uses for Macadamias

  • Sexual Tonics – perhaps the most unique use reported for macadamia nuts in in the treatment of sexual phobias.
  • Mulch – macadamia husks are generally returned to the field as mulch or used for compost material.
  • Potting Mix & Fuel – shells are sometimes used by flower growers for growing media, but their best use is as fuel.

Our other Macadamia Products

Macadamia cooking oil is one of the new gourmet cooking oils available. It is used by our own cafe and gives a great taste for food. It is competitively priced in either gift bottle or everyday use bottles, so why not give it a try?

Cosmetics: Macadamia oil can be refined to a cosmetic cream or massage oil. It has a silky non-greasy feel – the perfect gift for someone who thinks they have everything.

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Health Watch

Health watch alert!

Macadamia Meal

Considerable research has been conducted by our Macnut foodie experts into a product called Macadamia meal (ground macadamia nuts).

Mac Meal is extremely beneficial for people who suffer from food allergies such as flour, starch, and gluten.

It is also an advantage for people who are simply on a low carbohydrate diet with the aim to lose weight.

(The famous Dr Atkins was heard to quote on his diet regime “You can eat as many macadamias as you can afford on my diet”.)

Food allergy study has found the elimination of flour from the diet to be a very hard regime to stick to. Mac Meal can be used to make delicious muffins and  biscuits using nil flour.  These satisfy the comfort food cravings of sweet biscuits etc.

We all know that Almond meal (very expensive) is traditionally used for flour-free recipes, but Macadamia meal has the same, if not better effect. This fabulous ingredient can also be used for making all manner of recipes such as shortbread, sauces, pates, fudges, and is a superb topping for meat and vegetable dishes.

When using Mac nuts in a recipe, roasting them beforehand brings out their incredible, natural buttery flavour. This is not absolutely necessary, but we find roasting the nuts before cooking with them intensifies and compliments  the flavour of the most recipes.

Macadamia meal can be easily produced by zapping the pre-roasted nuts in your home blender using the pulse, until their texture starts to become fine with a few slightly larger chips. (Make sure you do not process for too long or it will become too fine and turn buttery.)


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Macadamia Processing


MacNut Farms is not just New Zealand’s largest macadamia orchard but also the largest macadamia processing facility. We process all our own orchard’s nuts as well as macadamias from many other orchards in the North Island. MacNut aims to be the processor of choice to NZ growers by offering an efficient and competitive service.The processing operation is broken into the stages detailed below:
Once the nuts are picked they are loaded into the hopper which feeds the dehusker (right). The dehusker has two rotating rollers which rip the tough outer husk from the nut. The brown nut that emerges has a moisture content of around 25% and weighs only about 46 % of the total. The huskings are composted and mixed with chicken litter to be used as fertiliser the following year. The hopper & dehusker
Macadamias hung out to dry To allow the nut to be cracked and the crunchy taste to develop they must be dried from 25% moisture after dehusking to 3% before cracking occurs. At MacNut this is a two stage process. First the nuts are stored in a green house, which allows moisture content to be reduced to less than 10%, then they are moved to a heated container with temperature between 40 – 50 deg C for a week to reduce the moisture to 3%. As you can see (above) we store our nuts in onion bags to allow airflow and easy handling. Each bag contains about 15 kg of nuts

The nuts leave the dryer and are put in the cracker hopper. The cracker consists of rotating knives that crack the nuts in a wedge shape.

The loose kernel and the nutshells then enter the trommel (shown below). The trommel is a rotating sieve with holes that get larger along its length. Small pieces fall out at the start and larger pieces further on, with any uncracked nuts rolling out the end to be re-cracked with the next batch

Once the pieces have fallen through the holes in the trommel the shell is separated from the kernel using air blowers. As the nut and shell fall down air passes upwards. The lighter shell pieces are blown upwards into collection bins while the denser kernel falls onto the conveyor belt for hand sorting.The trommel in action

The waste shell makes a beautiful and unique driveway surface at the orchard – always a source of interest with visitors. The local birds have developed a taste for macadamia scraps left in the shells on the driveway. We sell shell in bags or in bulk by special request.

On average we recover about 30 % of the nut weight as kernel the remaining 70 % is shell and waste.

The cracker and sorting operation is run on average 6 hrs a day, 5 days a week and can process around 500 kg of kernel each day. At the end of each day the equipment is cleaned and disinfected. Over a whole year MacNut Farms processes around 100 tonnes of nut in shell.

Sorting, Cooking and Packaging

The hard work starts once the kernel arrives on the conveyor belt. Here our staff separate the kernel into different types (chips, halves, wholes) and sizes. They also discard any bad or immature kernel and shell pieces.

The kernel is sold as raw, roasted and salted, chocolate coated, manuka honey coated, or our special Kiwimac. (half macadamia and half kiwifruit in chocolate). The chocolate coating is done under contract for us and returned packaged.

Hand sorting macadamiasTake a tip from us and taste our special large wholes in chocolate.  Most manufacturers who buy from us ask for small whole kernel so they can give you minimum kernel and maximum chocolate (which is cheaper) –  we give real value with maximum nut and enough chocolate … taste the difference!!

Another favourite variety is the roasted and salted nut, which is cooked on site. The bulk raw nut is lightly cooked in coconut oil in 2kg batches for 3 minutes, sprinkled with salt and excess salt and oil rubbed off to give a crisp and full flavoured product.

Each type is packed in bulk bins or boxes for shipment to our wholesale clients.

For our retail foil packs we carefully weigh and nitrogen purge to give you a long shelf life whether it be raw, salted or chocolate coated.

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Macadamia Nut Growers’ Guide – MacNut Farms


  • Location
  • Varieties
  • Planting
  • Pruning
  • Weed & Pest Control
  • Fertiliser
  • Yields
  • When to Harvest
  • Husking
  • NIS Drying & Storage
  • Transport to Processor
We have written this to answer questions on the growing, harvesting and transport of macadamias in NZ.  We do not consider ourselves experts in this field, and you would be better to contact a consultant than ask us about specific problems.  The information contained is purely advice that has been compiled from our experience and documents written by others.  We accept no liability for the accuracy or results of application in your circumstances.Location

Macadamias require temperate to tropical climates that are frost-free.  Present experience suggests that plantings will be most successful in the Auckland and regions further North.Macadamias prefer soil rich in organic matter but can tolerate a wide range of conditions from clay to sandy loam.  Main requirements are good drainage, a pH balance of 5-6, plenty of light, protection from wind when young and average rainfall or irrigation if very dry.  Macadamias dislike frosts or sitting in pools of water but otherwise are very tough.Trace minerals such as magnesium sulphate, zinc, boron will help as will organic nitrogen.


There are two main species of macadamia:

Macadamia tetraphylla comes from mid NSW and is more tolerant of cooler climates.  These trees tend to be vertical in growth and prickly with pink flowers and new growth.  Most rootstock is tetraphylla.

Macadamia integrifolia comes from Northern NSW and Queensland and prefers warmer climates, they are less prickly and rounder in shape.  The new growth is normally light green and flowers white.
Commercial varieties are inevitably hybrids, which show several of the characteristics of the above species.  In general NZ grows hybrids with tetraphylla characteristics.

Commercial macadamia trees are generally grafted from a good rootstock variety.

The main grafted varieties that have been planted in NZ are shown below.  These varieties have now been largely replaced by new and improved hybrids.  Advice should be sought from for the latest types suitable for NZ’s cooler climate.

A good quality nut that does best on warm sites but is difficult to pollinate.  Must be handpicked and may have too much vegetative growth on cooler or fertile sites.

Matures early and tends to drop nuts, a tetraphylla like hybrid that crops well and combines well with Beaumont as a pollinator.  Easily infected with veggie bug.  May need pruning to remove denseness.

A good self or cross pollinator which can crop heavily with smaller nuts and may require extra feeding.  The tree is less dense and prone to wind damage.

An open tree with good crop and is a good pollinator.  A good variety for home use with large and at times irregular nuts.

Own Choice
Another good variety for the domestic garden with good self or cross pollination, large nuts and few prickles (Integrifolia characteristics).  Tends to crop inconsistently and year round which is not much use commercially!

Attractive tree with inconsistent crops and many pink flowers in season.

There are many more varieties about which specific advice can be sought from a nursery.

As ground collection is generally unsuitable for NZ’s wet condition trees with good cropping characteristics and suitable for hand picking are preferred in NZ.

No planting of a single variety is recommended as macadamias do better when the various types are mixed to allow cross-pollination, thus increasing yields.


Macadamias are best planted in spring.

Trees should be planted in rows with a 6m row spacing and minimum 4m spacing between trees allowing for ingress of light, air and insects for pollination and room to grow to maturity.

Young trees can be protected by shelter belts, which can be removed later.  Mature trees still require some protection due to their brittle nature but large shelter belts will effect light levels and a balance must be sought.

If dry months are predicted an irrigation system may be useful. Ensure the water is of hygienic quality.


Some pruning is desirable after planting to reduce the tree to two leaders at each branching.

The tree should be manicured to allow for light, picking and air movement in the center.  The tree can be thinned to a minimum of internal branches without effecting production.  Height should be limited to picking height.  After pruning new growth may also need to be trimmed.

Weed & Pest Control

The main problem for NZ macadamias is the green vegetable bug, which can pierce the immature nut and stain the kernel brown, making it unsaleable.  We spray with Deltaphor 25 EC three times a season at intervals of three weeks, and 3 weeks after flowering (so pollination by bees is not affected).

After this period the nut should be hard enough to resist attack.  Towards the end of flowering (September) one preventative spray with Dipal for the Leaf Roller Caterpillar is advised.  Alternate measures for pest control include chickens or possibly wasps that will out-compete the veggie bug.

Where chemical control measures are undertaken ensure these measures are in compliance with health and safety regulations for application and the possibility of the retention of toxic residues.

Rats can be a problem and an eradication program is advised.  The rats often reside in bird’s nests or piles of rubbish or weeds and these should be removed.

Possums will eat soft greens nuts and goats the whole tree in early years (although goats prefer other trees to macadamias).

Trees should be kept clear of weeds using either a herbicide like ‘Roundup’, mowing or sheep.  (We use sheep, which do not disturb mature trees but are not good for ground harvesting)

Accurate records of pest and weed control measures will allow optimisation in future years.


Annual leaf and soil analysis should show up deficiencies and point towards a fertiliser program.

Applications of trace elements can be achieved in airborne sprays.

In addition ground based applications of superphosphate or organic manure or mulch can provide valuable nutrients.  In particular a good source of mulch will be the prunings and husks from the nuts.

Avoid heavy application of nitrogen in summer as this can promote vegetative growth at the expense of nut quality and quantity.
Accurate records will help determine the effectiveness of any program.


Top orchards in NZ have returned yields of 4-6 tonnes per hectare.

To estimate the crop sizes for a well-tended orchard use the following as a guide:

Tree Age Kg per Tree
5 2
6 5
7 8
8 10
11 15
25 55
Orchards not achieving above 2 tonnes per hectare could have basic location or nutritional problems.  Specialist advice should be sought.When To HarvestMacadamias in NZ tend to hand picked due to wet soil conditions, so it is important to pick between when the nuts are ripe and when the nuts drop.Normally the nuts are ripe by June and this can be assessed by observing nuts dropping, splitting on the tree.  To test for maturity: when opened the nut husk interior and the nut should both be brown (not white).Nuts are picked by pulling or cutting the racemes from the tree and may be collected efficiently by placing nets under the tree.The harvest of immature nuts will result in many small and hard kernels which must be hand sorted out and reduce the value of the crop.Husking

Nuts should be husked within 24 hours of picking to prevent respiratory heat in storage, which can in turn increase mould, rancidity and germination.  If the nut cannot be husked immediately the nut in husk should be well ventilated and dry.
Rocks and debris of a large nature should be removed from nuts before husking.  Husking machinery should be checked to ensure that the nuts are not being cracked or bruised in the process.

NIS (Nut in Shell) Drying & Storage

Moisture after dehusking is normally around 25% and must be reduced to around 1.5% for cracking.  Nuts should be crisp when fully dry and will rattle when shaken to indicate that the kernel has shrunk away from the shell.

Nuts should be hung in a well-ventilated place to reduce moisture content before transport to the processor.  The minimum moisture content that can be achieved without commercial drying is around 10%.  Failure to store in a dry well ventilated pace will lead to mould, rancidity and germination.

Contamination or wetting of nuts in storage should be of highest concern with special attention paid to ensure that no condensation in the storage area or leakage from outside can occur.

Avoid prolonged exposure to direct sunlight, which can increase rancidity and cracking of the shell.

If using heating in the drying process do not use temperatures in excess of 38 deg C if the NIS moisture content is above 10% as this can create browning of the kernel.

Do not store nuts for prolonged periods at moisture contents greater than 10%.

Transport To Processor

Take precautions to ensure chemicals, foreign debris or manure during transport does not contaminate the nuts.  Cover the macadamias during transport to ensure the nuts arrive dry and clean.

Avoid drop heights greater than 2m as nuts may be cracked or bruised in handling.

Delivery to processing should be immediate after removal from well-ventilated dry storage.  Transport times greater than 24 hours can result in increases in rancidity and mould.

Ensure adequate information about type, time of picking and storage conditions is provided to the processor to allow optimum processing.  Label any nuts to identify ownership and date of transport.


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History of the Macadamia

Mt Warning, New South Wales – home of the macadamia nut
The macadamia is the only major commercial food crop that is native to Australia.The colonization of Australia by the British began in 1788 but it wasn’t until 1875 that the recorded history of the macadamia began. Ferdinand Von Muller, Royal Botanist at Melbourne and Walter Hill, Director of the Botany Garden at Brisbane, were botanizing in the forest along the Pine River in the Moreton Bay district of Queensland. They discovered a species of tree in the family Proteaceae previously unknown to European and American Botanists. This species did not fit into any previously established genera in that family, so in 1858 Muller established a new genus, Macadamia, naming it in honor of John Macadam, MD, Secretary of the Philosophical Institute of Victoria.Of course, the British weren’t the first inhabitants of Australia. At the time of their arrival Australia was inhabited by aborigines, with a population of around 300,000. Their food consisted mainly of fish, shellfish, turtle eggs, grubs of certain tree bark insects, kangaroo, koala, wombat, bandicoot, other small animals and birds, plus yams, and grass seeds.
However, during the months of fall and winter (March to June), they would come from far and near to congregate on the eastern slopes of the Great Divide Range. Here they would feast on the seeds of two kinds of trees which were abundant in the area. One kind of tree they called “Kindal Kindal”, which we now know as the macadamia.The macadamia genus consists of at least ten species, but only two of those produce edible nuts, the Integrifolia and the Tetraphylla.
The first large planting of Macadamias occurred in 1890 on the Frederickson Estate at Rous Mill, New South Wales. They planted around 250 trees as a source of nuts for the family. Many of those trees still exist and are still producing a good crop of nuts.Interestingly, the largest single planting of macadamia trees is on 3,700 acres in Komatipoort, South Africa. Additionally, macadamias are grown commercially in Hawaii, Australia, Malawi, Kenya, South Africa, Israel, Costa Rica, Guatemala, Mexico, Brazil, and many other tropical and subtropical regions, including Florida.Macadamias were first grown in NZ through ad-hoc import from Australia.In 1975 the beginnings of commercial plantings occurred south of Auckland through the efforts of Virginia Warren. This enterprise has flourished into a cottage industry with around 400 trees planted.Planting began at what is now MacNut Farms in 1980 under the management of Neil Whitehead, with the orchard starting to produce commercial quantities in 1989. Neil continued  as manager until 1997, supervising the development of NZ’s largest orchard at 10,500 trees spread over 105 acres.MacNut Farms is predominantly planted in a hybrid species called “Beaumont”, which is known for it’s superior tasting nut. In NZ, Beaumont’s must be handpicked, as they do not drop their nuts. Most Australian and Hawaiian species drop their nuts, allowing for a cheaper ground harvest.


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Growing Macadamias


Macadamias thrive in the following conditions:

  • High rainfall
  • Well drained soil
  • Warm and frost free climate
  • Some wind shelter

Macadamia trees are extremely tough – in fact they’re quite hard to kill. They produce economic quantities of fruit after 8 years, although fruit will be borne in small quantities as early as two years. Trees live for 70 years or more, reaching a height of 20 metres. At MacNut Farms we have the ingredients for a successful orchard, although a little more warm weather wouldn’t go astray.

The growing year at South Head is broken into the following phases:

Flowering and Pollination: OctoberThe trees flower during October with long white and pink racemes making this the best time of year to visit the orchard. At this time of the year the orchard is home to beehives to assist in pollination and ceases picking operations to minimise disturbance to the flowers. The Beaumont hybrid that dominates at MacNut Farms has been planted with other varieties to improve its poor self-pollination.
Pest Control and Weed Removal: late Spring to AutumnOver the warm summer months the picking is finalised and the trees are sprayed with liquid fertilisers and veggie bug control agents. At the same time the prolific growth of weeds is controlled by sheep and maintenance around the trees. Further fertilising with mulch from the husks, chicken litter and some chemical fertilisers is completed at this critical stage of growth as the new nuts set and grow on the trees. Macadamia trees are biennial, alternating heavy and light cropping years.



Picking, Pruning: Winter and Early SpringAt the start of June the picking season begins. Picking in NZ is done by hand as the Beaumont hybrid does not drop it’s nuts.  In Australia mechanical harvesting from the ground is the norm. The racemes of nuts are clipped from the trees and are collected in nets placed on the ground.
It is common practice to have a pruning gang working just in front of picking gangs. In this way access to the trees is improved and high branches can be cut and left on the ground for picking. Over the past two years we have pruned the orchard to allow better air flow for pollination, more light ingress, better access for picking and allowing the trees to put more of their growing effort into fruiting.From 1997 to 1999 MacNut Farm production has increased from 20 tons to over 40 tons of nut in shell.


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